Issue with Running Python application in Lambda in AWS Academy

I am trying to create a serverless Watermark application using AWS Lambda, S3 and API. I have code in the Lambda function inline code. However if I run or even test, I keep getting an error

[ERROR] Runtime.ImportModuleError: Unable to import module ‘lambda_function’: No module named ‘PIL’

I already crated a layer in the lambda function with Pillow but still have the error. I also tried to combine the Pillow and code, uploaded as Zip but still have the same error. I also tried different Python runtime 3.8, 3.9 but still get the same error. Any support would be appreciated.