To get in, you have to have a really huge mental breakdown of all thats happened during your stay in the backrooms, you cant fake a mental breakdown. after giving up and just doing nothing, this level is non other than your mind.
You're in a long hall running towards the light,
3 paths then you stop to see 3 things
1 noclipping was just you hitting your head against anything hard(says your memory or mind)your in some kind of comma for several years(the mind could have changed time to make it look like some freak accident)
You have a choice to go back but several things have happened, some of your family members have passed, maybe your loved pet has passed or anything you loved is gone, you can go back to the real world if you want but there are 2 more choices.
2. you see a alternate reality you happy with everything the same, you never went to the backrooms, but in reality you are still trapped in your mind you know that, that isn't real, its all fake, its not the same.
3. this is to much, you just want to rest, nothing, your just in a void resting not feeling or seeing or thinking anything just nothing.