SLS existing S3 lambda trigger

serverless.yml

functions:
  TriggerFunc:
    handler: handlers.main
  
resources:
  Resources:
  
    # Bucket 'TriggeredBucket'
    TriggeredBucket:
      Type: AWS::S3::Bucket
      DependsOn:
        - TriggerFuncLambdaPermissionTriggeredBucketS3
      Properties: 
        BucketName: my-unique-bucket-name
        NotificationConfiguration:
          LambdaConfigurations:
            - Event: s3:ObjectCreated:*
              Function:
                Fn::GetAtt:
                  - TriggerFuncLambdaFunction
                  - Arn
        CorsConfiguration:
          CorsRules:
            - AllowedHeaders:
                - "*"
              AllowedMethods:
                - PUT
              AllowedOrigins:
                - "*"
    
    # Lambda 'TriggerFunc' bucket permission
    TriggerFuncLambdaPermissionTriggeredBucketS3:
      Type: AWS::Lambda::Permission
      DependsOn:
        - TriggerFuncLambdaFunction
      Properties:
        FunctionName:
          Fn::GetAtt:
            - TriggerFuncLambdaFunction
            - Arn
        Action: lambda:InvokeFunction
        Principal: s3.amazonaws.com
        SourceArn: arn:aws:s3:::my-unique-bucket-name