The above one doesnt work because i dont know where it should be located. The second one works, but i’d prefer VS to find it automatically so the interfaces probably would be found too…
I tried new generating of project files, adding “OnlineSubsystem” in ProjectName.Build.cs
There is a file with the name “PutYourProjectNameHere.build.cs” at the root directory of your source files. Inside it there is an array of public dependency modules of Your project. You need to add the name of the modules you are using to this array. In your case it seems to be “OnlineSubsystem” and “OnlineSubsystemUtils”. After adding those two you should be able to include the header using only the name like in the picture.