i am a bit confused with the question. not sure what you’re asking.
it seems to me you want to create some environments (to avoid saying world/map/level which has specific meaning).
and then distritube them.
you can either check some plugins to do dlc.
or use the paks to do dlc.
or search online for dlc.
if you can ship your app with the levels, then just include them in your game.
if you want the player to edit the levels, you have to implement that yourself.
and you’ll also need to implement a way to serialize that.
you can look at the savegame functionality.