Setting Up an S3 Trigger for an AWS Lambda Function in the AWS Clouformation

AWSTemplateFormatVersion: "2010-09-09"
Description: "Create Lambda S3 triggger"

Parameters:
  MyBucketName:
    Description: S3 Bucket Name
    Type: String
    Default: abhaysingh091290

Resources:
  MyIAMRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: 2012-10-17
        Statement:
          - Effect: Allow
            Principal:
              Service:
                - lambda.amazonaws.com
            Action:
              - sts:AssumeRole
      Policies:
        - PolicyName: MyPolicy
          PolicyDocument:
            Version: 2012-10-17
            Statement:
              - Effect: Allow
                Action:
                  - s3:ListBucket
                Resource: arn:aws:s3:::${MyBucketName}
  LambdaPermission:
    Type: AWS::Lambda::Permission
    Properties:
      Action: 'lambda:InvokeFunction'
      FunctionName: !Ref MyFunction
      Principal: s3.amazonaws.com
      SourceArn: !Sub 'arn:aws:s3:::${MyBucketName}'
      SourceAccount: !Ref AWS::AccountId
  MyFunction:
    Type: AWS::Lambda::Function
    Properties:
      Code:
        ZipFile: |
          def handler(event, context):
            return "Hello, World!"
      Handler: index.handler
      Role: !GetAtt MyIAMRole.Arn
      Runtime: python3.8
      Timeout: 30
  MyBucket:
    Type: AWS::S3::Bucket
    Properties:
      BucketName: !Ref MyBucketName
      NotificationConfiguration:
        LambdaConfigurations:
          - Event: s3:ObjectCreated:*
            Function: !GetAtt MyFunction.Arn
            Filter:
              S3Key:
                Rules:
                  - Name: Suffix
                    Value: ".txt"
                  - Name: Prefix
                    Value: "test-"