Is it not possible to have parameterized constructors?

I’m not sure even if you do get your class to compile with a parametered constructor, if its useful. Actors are usually spawned using the UWorld::SpawnActor function which doesn’t give you an option to include constructor parameters. What is the reason you want to pass the parameters in the constructor, rather than right after construction?

If you want certain values to be set before OnConstruction or BeginPlay or another initialization related function, you can use deferred actor spawning to do this. Spawning an actor causes it to not finish initialization immediately, allowing you to set values before OnConstruction, BeginPlay etc are called. Check out UWorld::SpawnActorDeferred or search for deferred actor spawning. Would that method be satisfactory for you?