If we are in a simulation it is like a computer simulating mario-brothers, not like a bunch of us in pods with a brain wire into our heads like Matrix. So there is no 'escape' into a world where our bodies are.... our (simulated) bodies are here.

So there is no back door, just as their is no back door for the characters in Mario-Brothers to escape their game.

Of course is Mario were sentient, he could try to reverse engineer the computer playing his game, and introduce play his game in a way as to crash or hack that computer. (quite a stretch, since most hacks come from the outside.) or perhaps he communicates with one of us outside the game, and convinces them to introduce the hack.

Then he could send a probe out into our world... But mario himself cannot be here.

this I think would be the situation if we are indeed simulated.