What password that use in identity for Apppool

I try to install Orchestrator but i don’t know user and password in this step. How to register user and password. I use UiPath Platform trial version for 60 days.

This is only necessary if you need to use a custom account to run the application pool. Then you have to create the account first and grant it the necessary rights.
If you dont NEED to use a custom account you can check the “Application Pool Identity” box and it will use a default IIS App-pool identity.