Python AWS Lambda Url invokes twice

I seem to have a problem with my lambda function. My function invokes only once when I test it on AWS. However, when I invoke the lambda function through the function URL it executes twice! Has anyone experienced this before?

import json
import boto3

dynamodb = boto3.resource('dynamodb')
ddbClient = boto3.client('dynamodb')

def LatestDBrow():
...
    return row


#Invoke lambda function
def lambda_handler(event, context):
    
    scratchPadlist = []
    scratchPadlist = LatestDBrow()
    
    #print(scratchPadlist)
    
    #Put TS row into variables
    inBatchTrial = scratchPadlist[0]
    inNoOfUsersProcessed = scratchPadlist[1]
    inl1Alpha = scratchPadlist[2]
    inl1Beta = scratchPadlist[3]
    
    
    #Update wanted values
    inBatchTrial += 1
    inl1Alpha = 1
    inl1Beta = 1
                                                     
    TableColNames = ['Batch Trial','No. of users processed','L1 Alpha',
                           'L1 Beta','L1 N','L1 Rewards',
                           'L1 Click Pct','L2 Alpha','L2 Beta',
                           'L2 N','L2 Rewards','L2 Click Pct',
                           'Next Page Shown']
                           
    TSlist =    [inBatchTrial, inNoOfUsersProcessed, inl1Alpha,
                    inl1Beta, inl1N, inl1Rewards,
                    inl1ClickPct, inl2Alpha, inl2Beta,
                    inl2N, inl2Rewards,inl2ClickPct,
                    innextPageShown]
    
    dbDict = {TableColNames[i]: str(TSlist[i]) for i in range(len(TableColNames))}

    table1 = dynamodb.Table("TestDB")
    table1.put_item(Item = dbDict)