Power Platform DevOps Tools new environment creation task

I am trying to set up the Azure pipeline for Power Platform environment creation. I have created the App Registration in Azure AD. Now I am struggling to create the Power Platform service connection to be used by the environment creation task. What should I put for the server url since the environment doesn't exist yet? Also one of the pre-requisite is to add the registered App ID to the Power Platform environment and assign a security role. In my case since the environment doesn't exist yet how is this user association created? Any help is much appreciated, I am really not sure what I might be missing.