Is it possible to "Join a site from the command line" for Portal?
Is there any build in logic in Install Portal for ArcGIS on Linux silently—ArcGIS Enterprise | Documentation for ArcGIS Enterprise to join a Portal when setting up a HA deployment?
I have no browser access until the deployment is fully completed...
There is a tool for Server ot Join an existing site—ArcGIS Server | Documentation for ArcGIS Enterprise