Get username who invoked an unattended process in Apps

Hello,

I have create an App which invokes a process when the button is clicked.

The process runs unattended, on a remote machine.
I gave access to more users using the Permissions tab. During the process I want to know which user invoked the process. Is there a way to find that out? I need to pass its email as an argument to the process which is being invoked.

Replying to myself, apparently it is not supported → Assign user to variable inside App - #5 by Michaeljep