How to load scene with async + delay

Hello Everyone, how I can load a scene with async (I want the scene to load in the background and I think I need to use async), but I don’t know how to use it! Can anyone help me to make this script that runs async after 5 seconds? I want to transfer the player from PreMenu scene to MainMenu scene. I tried everything but I always have an error!

Please, someone, send me a script!

BTW: I’m using the latest version of Unity!

I extended loading scene, by adding DontDestroyOnLoad on Camera and GUI. And then I check OnSceneLoad, If It is not mainmenu screen, then startcoroutine which waits 1s and then Destroy undestroyed things from previous scene and switching to new scene camera, setting bool which says it is finally loaded. Which prevented for example playing, while loading.