Hi anonymous user
I can see 500 error is coming from the function app while executing it. I will suggest testing the function app use the same input when you have observed the error. If you are still facing any issues please let me know so I can connect with you offline to assist you further.
Update 12/8:
Sharing our offline discussion
We looked into the source of the function app and fix the issue while communicating with storage. Suggested some changes for excel operation. Deployed the function app with the correct application setting used in the code. We tested the scenario but still observe 500 errors so we enable tracing and found that the logic app was not passing the right parameter to the function app and while communicating with the storage account the file was passed empty thus throwing the 500 error from the function.
We have fixed parameters in the logic app and you confirmed that it was working as expected.