Spawn actor in sublevel

I’m running this script in the blueprint of an actor (in my persistant level) that makes the level open on boxtrigger.
I have created the spawners by just placing them in the level.
I do know that it’ll make the actor at the same location, I just want it to work for the index 0 and then change it later.

I just tried to print the length of the array and it always shows 0.

I’m new to UE4 so I might have done a mistake with the level thing. I just used the “open level” function in order to have the player teleported to the next level, which works.

thanks for your answer