To add an AWS Custom Resource to CloudFormation template and provide an AWS Lambda Function

The site below has a Lambda sample that deletes objects in an S3 bucket.
https://stackoverflow.com/questions/40383470/can-i-force-cloudformation-to-delete-non-empty-s3-bucket
Only the "requests" module has changed.
Create a Lambda function with the code below.
Create a "requests" layer in your Lambda function.

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import json
import boto3
import requests


def lambda_handler(event, context):
    try:
        bucket = event['ResourceProperties']['BucketName']

        if event['RequestType'] == 'Delete':
            s3 = boto3.resource('s3')
            bucket = s3.Bucket(bucket)
            for obj in bucket.objects.filter():
                s3.Object(bucket.name, obj.key).delete()

        sendResponseCfn(event, context, "SUCCESS")
    except Exception as e:
        print(e)
        sendResponseCfn(event, context, "FAILED")


def sendResponseCfn(event, context, responseStatus):
    response_body = {'Status': responseStatus,
                     'Reason': 'Log stream name: ' + context.log_stream_name,
                     'PhysicalResourceId': context.log_stream_name,
                     'StackId': event['StackId'],
                     'RequestId': event['RequestId'],
                     'LogicalResourceId': event['LogicalResourceId'],
                     'Data': json.loads("{}")}

    requests.put(event['ResponseURL'], data=json.dumps(response_body))

Specify the ARN of Lambda in the custom resource as follows.

AWSTemplateFormatVersion: '2010-09-09'

Resources:
  myBucketResource:
    Type: AWS::S3::Bucket
    Properties:
      BucketName: test-bucket

  LambdaUsedToCleanUp:
     Type: Custom::cleanupbucket
     Properties:
       ServiceToken: arn:aws:lambda:us-west-2:XXXXXXXXXXXX:function:lambda_function_name
       BucketName: !Ref myBucketResource

Hi, this may be what you're looking for: https://adriandrummond.com/2019/04/02/how-to-delete-s3-bucket-contents-in-cloudformation/