Same here. They mention that we need a specific p4ignore file even if we load the source from github (loading it from Perforce directly would need a custom license with Epic Games apparently). Unfortunately, the p4ignore file isn’t shared anywhere. Even in the “recent” (2020) stream (Version Control Fundamentals | Live from HQ | Inside Unreal | Livestream) they only mentioned access to the Epic Games Perforce server but not how we could setup source build and UGS from github mentioned in the docs (like here: Using Precompiled Binaries in Unreal Game Sync for Unreal Engine | Unreal Engine 5.0 Documentation ).
Maybe @ArranLangmead who hosted the stream can get us at least the ignore file / typemap so we don’t have to painstakingly put it together ourselves? That would really, really help us a lot 
This way we could pull it from github, move it into p4 and go the UGS route with precompiled binaries. Then just pull updates from github, merge, recompile and let UGS to its thingys.