Using Animator IK how can I detect when the player hand finished move forward?

using UnityEngine;
using System;
using System.Collections;
using UnityEngine.UI;
using System.Collections.Generic;

[RequireComponent(typeof(Animator))]
public class IKControl : MonoBehaviour
{
    public InteractableItem[] lookObj = null;
    public GameObject objToThrow;
    public Text text;
    public float weightDamping = 1.5f;
    public float maxDistance = 10f;
    public bool RightHandToTarget = true;
    public float throwSpeed;
    public bool handFinishedMove = false;

    private List<InteractableItem> allDetectedItems;
    private Animator animator;
    private InteractableItem lastPrimaryTarget;
    private float lerpEndDistance = 0.1f;
    private float finalLookWeight = 0;
    private bool transitionToNextTarget = false;

    void Start()
    {
        animator = GetComponent<Animator>();
        allDetectedItems = new List<InteractableItem>();
    }

    // Callback for calculating IK
    void OnAnimatorIK()
    {
        if (lookObj != null)
        {
            InteractableItem primaryTarget = null;
            float closestLookWeight = 0;

            // Here we find the target which is closest (by angle) to the players view line
            allDetectedItems.Clear();
            foreach (InteractableItem target in lookObj)
            {
                Vector3 lookAt = target.transform.position - transform.position;
                lookAt.y = 0f;

                // Filter out all objects that are too far away
                //if (lookAt.magnitude > maxDistance) continue;
                if (lookAt.magnitude > target.distance) continue;

                float dotProduct = Vector3.Dot(new Vector3(transform.forward.x, 0f, transform.forward.z).normalized, lookAt.normalized);
                float lookWeight = Mathf.Clamp(dotProduct, 0f, 1f);
                if (lookWeight > 0.1f && lookWeight > closestLookWeight)
                {
                    closestLookWeight = lookWeight;
                    primaryTarget = target;
                    allDetectedItems.Add(target);
                }
            }

            if (primaryTarget != null)
            {
                if ((lastPrimaryTarget != null) && (lastPrimaryTarget != primaryTarget) && (finalLookWeight > 0f))
                {
                    // Here we start a new transition because the player looks already to a target but
                    // we have found another target the player should look at
                    transitionToNextTarget = true;
                }
            }

            // The player is in a neutral look position but has found a new target
            if ((primaryTarget != null) && !transitionToNextTarget)
            {
                if(primaryTarget.actionwithoutthrow == true)
                {
                    RightHandToTarget = true;
                }

                lastPrimaryTarget = primaryTarget;
                //finalLookWeight = Mathf.Lerp(finalLookWeight, closestLookWeight, Time.deltaTime * weightDamping);
                finalLookWeight = Mathf.Lerp(finalLookWeight, 1f, Time.deltaTime * weightDamping);
                float bodyWeight = finalLookWeight * .75f;
                animator.SetLookAtWeight(finalLookWeight, bodyWeight, 1f);
                animator.SetLookAtPosition(primaryTarget.transform.position);

                if (RightHandToTarget && primaryTarget.interactableMode == InteractableItem.InteractableMode.Action
                    || RightHandToTarget && primaryTarget.interactableMode == InteractableItem.InteractableMode.ActionWithoutThrow)
                {
                    Vector3 relativePos = primaryTarget.transform.position - transform.position;
                    Quaternion rotationtoTarget = Quaternion.LookRotation(relativePos, Vector3.up);
                    animator.SetIKRotationWeight(AvatarIKGoal.RightHand, finalLookWeight);
                    animator.SetIKRotation(AvatarIKGoal.RightHand, rotationtoTarget);
                    animator.SetIKPositionWeight(AvatarIKGoal.RightHand, finalLookWeight * 1f * closestLookWeight);
                    animator.SetIKPosition(AvatarIKGoal.RightHand, primaryTarget.transform.position);

                    // -> new code block
                    if (finalLookWeight > 0.95f) // here you can play with a value between 0.95f -> 1.0f
                    {
                        handFinishedMove = true;

                        if(primaryTarget.action == true && primaryTarget.interactableMode == InteractableItem.InteractableMode.Action)
                        // call your funtion to shoot something here
                        StartCoroutine(ThrowObject(objToThrow.transform, primaryTarget.transform.position, 30f));
                    }
                }
            }

            // Let the player smoothly look away from the last target to the neutral look position
            if ((primaryTarget == null && lastPrimaryTarget != null) || transitionToNextTarget)
            {
                finalLookWeight = Mathf.Lerp(finalLookWeight, 0f, Time.deltaTime * weightDamping);
                float bodyWeight = finalLookWeight * .75f;
                animator.SetLookAtWeight(finalLookWeight, bodyWeight, 1f);
                animator.SetLookAtPosition(lastPrimaryTarget.transform.position);

                if (RightHandToTarget)
                {
                    Vector3 relativePos = lastPrimaryTarget.transform.position - transform.position;
                    Quaternion rotationtoTarget = Quaternion.LookRotation(relativePos, Vector3.up);
                    animator.SetIKRotationWeight(AvatarIKGoal.RightHand, finalLookWeight);
                    animator.SetIKRotation(AvatarIKGoal.RightHand, rotationtoTarget);
                    animator.SetIKPositionWeight(AvatarIKGoal.RightHand, finalLookWeight * 0.5f * closestLookWeight);
                    animator.SetIKPosition(AvatarIKGoal.RightHand, lastPrimaryTarget.transform.position);
                }

                if (finalLookWeight < lerpEndDistance)
                {
                    transitionToNextTarget = false;
                    finalLookWeight = 0f;
                    lastPrimaryTarget = null;
                }
            }

            // Show primary object found by the player
            if (primaryTarget != null)
            {
                text.text = primaryTarget.description;
            }
            else
            {
                text.text = "";
            }
        }
    }

    IEnumerator ThrowObject(Transform objectToMove, Vector3 toPosition, float duration)
    {
        float counter = 0;

        while (counter < duration)
        {
            counter += Time.deltaTime;
            Vector3 currentPos = objectToMove.position;

            float time = Vector3.Distance(currentPos, toPosition) / (duration - counter) * Time.deltaTime;

            objectToMove.position = Vector3.MoveTowards(currentPos, toPosition, time);

            yield return null;
        }
    }
}

I added a new flag name handFinishedMove and tried to use it in line 99 set it to true :

if (RightHandToTarget && primaryTarget.interactableMode == InteractableItem.InteractableMode.Action
                    || RightHandToTarget && primaryTarget.interactableMode == InteractableItem.InteractableMode.ActionWithoutThrow)
                {
                    Vector3 relativePos = primaryTarget.transform.position - transform.position;
                    Quaternion rotationtoTarget = Quaternion.LookRotation(relativePos, Vector3.up);
                    animator.SetIKRotationWeight(AvatarIKGoal.RightHand, finalLookWeight);
                    animator.SetIKRotation(AvatarIKGoal.RightHand, rotationtoTarget);
                    animator.SetIKPositionWeight(AvatarIKGoal.RightHand, finalLookWeight * 1f * closestLookWeight);
                    animator.SetIKPosition(AvatarIKGoal.RightHand, primaryTarget.transform.position);

                    // -> new code block
                    if (finalLookWeight > 0.95f) // here you can play with a value between 0.95f -> 1.0f
                    {
                        handFinishedMove = true;

                        if(primaryTarget.action == true && primaryTarget.interactableMode == InteractableItem.InteractableMode.Action)
                        // call your funtion to shoot something here
                        StartCoroutine(ThrowObject(objToThrow.transform, primaryTarget.transform.position, 30f));
                    }
                }

Then in another script : but handFinishedMove is never true.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class UnlockCrate : MonoBehaviour
{
    public GameObject carte;
    public Animation anim;
    public IKControl ikControl;

    private bool playAnimOnce = false;

    private void Update()
    {
        var distance = Vector3.Distance(carte.transform.position, transform.position);

        if (distance < 1.5f)
        {
            if (!playAnimOnce)
            {
                if(ikControl.handFinishedMove == true)
                {
                    anim.Play("Crate_Open");
                }

                playAnimOnce = true;
            }
        }
        else if (playAnimOnce)
        {
            anim.Play("Crate_Close");
            playAnimOnce = false;
        }
    }
}