How to use WinSCP library within Azure FunctionApp application

It seems fine when I run the Function App locally (C#). However after successful deployment to Azure Function App environment, and triggering within the Logic App environment, the Funciton app never returns. I suspect it has something to do with spin-off winscp.exe.

Please help.

Did you follow the instructions?
SFTP/FTPS file transfers in Microsoft Azure Function
What does the log say?