Ok so I figured this one out. The reason I struggled so much with this was that last time I did this in Unreal 4 it was not a necessary step.
In Unreal 5 however, it was necessary to uncomment the line about enabling online subsystems in the build.cs file
I also had to enable the EOS plugins in Unreal Engine, which seems obvious but as I recall, in UE4, including the SDK was enough to enable it. Evidently UE5 is different. Anyway, hope this helps anyone who has the same problem
