Do you mean the Window pin?
I use my PC for streaming games via Steam as well and my solution was twofold:
- Change my windows auth from pin to password.
- Store my windows password, so it never requires it when booting.
This guide will probably get you started. My game server is still on windows 10, so the process might be different on 11.
https://www.technipages.com/windows-11-how-to-turn-on-auto-login/
EDIT
You probably mean a moonlight pin, in which case I don't think I'll be much help. Apologies