Hello, I believe it’s done this way.
AFPSGameMode::AFPSGameMode()
{
// set default pawn class to our Blueprinted character
static ConstructorHelpers::FClassFinder<APawn> PlayerPawnClassFinder(TEXT("/Game/Blueprints/BP_Player"));
DefaultPawnClass = PlayerPawnClassFinder.Class;
// use the custom HUD class
HUDClass = AFPSHUD::StaticClass();
}