Unity - How to set the color and UV map of an individual face when clicking a mesh?

i saw Unity - How to set the color of an individual face when clicking a mesh? this Question and I'm challenging this. However, I have no understanding of how to reconstruct UV. If there's anyone who can tell me which part to modify in the code below, I'd like to get help.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using System.Linq;
public class meshColor : MonoBehaviour
{
    public GameObject cube;

    [SerializeField] private MeshFilter meshFilter;
    [SerializeField] private MeshRenderer meshRenderer;
    [SerializeField] private MeshCollider meshCollider;

    private Mesh _mesh;

    private void Awake()
    {
        if (!meshFilter) meshFilter = GetComponent<MeshFilter>();
        if (!meshRenderer) meshRenderer = GetComponent<MeshRenderer>();
        if (!meshCollider) meshCollider = GetComponent<MeshCollider>();

        _mesh = meshFilter.mesh;

        var colors = new Color[_mesh.vertices.Length];
        for (var k = 0; k < colors.Length; k++)
        {
            colors[k] = Color.white;
        }

        _mesh.colors = colors;
    }

    private void Update()
    {
        if (!Input.GetMouseButtonDown(0)) return;

        var ray = Camera.main.ScreenPointToRay(Input.mousePosition);

        if (Physics.Raycast(ray, out var hit))
        {
            Debug.Log(hit.triangleIndex);
                
            var vertices = _mesh.vertices;
            var uvs = _mesh.uv;
            var triangles = _mesh.triangles;
            var colors = _mesh.colors;
                    
            var vert1Index = triangles[hit.triangleIndex * 3 + 0];
            var vert2Index = triangles[hit.triangleIndex * 3 + 1];
            var vert3Index = triangles[hit.triangleIndex * 3 + 2];
                    
            var vert1Pos = vertices[vert1Index];
            var vert2Pos = vertices[vert2Index];
            var vert3Pos = vertices[vert3Index];

            var uv1Pos = uvs[vert1Index];
            var uv2Pos = uvs[vert2Index];
            var uv3Pos = uvs[vert3Index];

            var vert1Occurrences = 0;
            var vert2Occurrences = 0;
            var vert3Occurrences = 0;
            foreach (var index in triangles)
            {
                if (index == vert1Index) vert1Occurrences++;
                else if (index == vert2Index) vert2Occurrences++;
                else if (index == vert3Index) vert3Occurrences++;
            }
        
            var newVertices = vertices.ToList();
            var newColors = colors.ToList();
            var newUvs = uvs.ToList();
        
            if (vert1Occurrences > 1)
            {
                newVertices.Add(vert1Pos);
                newColors.Add(new Color());
                newUvs.Add(uv1Pos);
                vert1Index = newVertices.Count - 1;
            }

            if (vert2Occurrences > 1)
            {
                newVertices.Add(vert2Pos);
                newColors.Add(new Color());
                newUvs.Add(uv2Pos);
                vert2Index = newVertices.Count - 1;
            }

            if (vert3Occurrences > 1)
            {
                newVertices.Add(vert3Pos);
                newColors.Add(new Color());
                newUvs.Add(uv3Pos);
                vert3Index = newVertices.Count - 1;
            }
        
            triangles[hit.triangleIndex * 3 + 0] = vert1Index;
            triangles[hit.triangleIndex * 3 + 1] = vert2Index;
            triangles[hit.triangleIndex * 3 + 2] = vert3Index;

            newColors[vert1Index] = Color.red;
            newColors[vert2Index] = Color.red;
            newColors[vert3Index] = Color.red;

            newUvs[vert1Index] = new Vector2(uv1Pos.x, uv1Pos.y);
            newUvs[vert2Index] = new Vector2(uv2Pos.x, uv2Pos.y);
            newUvs[vert3Index] = new Vector2(uv3Pos.x, uv3Pos.y);

            _mesh.vertices = newVertices.ToArray();
            _mesh.triangles = triangles;
            _mesh.colors = newColors.ToArray();
            _mesh.uv = newUvs.ToArray();

            _mesh.RecalculateNormals();
        }
        else
        {
            Debug.Log("no hit");
        }
    }
}