I never said anything about opening something from older version of Unreal in Unreal version 5.
You got confused by this:
P.s. Unreal documentation sucks, many things are not documented, there are zero examples and many times documentation is simply outdated e.g. - they copied something that was no longer supported from UE version 4.16 to 5.0.
Here I am blaming bad Unreal documentation. This has nothing to do with the issue I am having.
My issue is: I do not know how to load a level from a .pak file.
I need working code example.