Hello KooHyun,
I hope this message finds you well. I'm Trong, a developer in the AWS development team here at Mendix. I read through your forum post and the previous question you referenced. Sorry that it took us so long to get back to you. I'd like to try and help guide you through your challenge.
From what I understand, you're trying to accomplish the following:
Is this correct? If not, could you provide a little more detail about what you mean when you refer to a "file manager"? Are there specific functions or features that you're looking for when connecting this file manager with Amazon S3?
However, to provide the most relevant solution for your problem, I need a better understanding of your specific needs. Your clarification will be instrumental in guiding the next steps.
If you have any more questions or if something isn't clear, don't hesitate to reach out to me directly. You can send me a private message if you go to my developer profile and click on "Contact".
Best,
Trong