Bill Cipher: Escape from Axolotl

So, after all his misdeeds, Bill Cipher was imprisoned in the Axolotl prison. And what do you think this yellow triangle will try to do all the time? That's right, escape!
🔑Collect all the yellow keys (they are a little oddly shaped) to open the exit!
😳Be careful! After all, the Axolotl himself is wandering through the labyrinths of the prison...
❗Find the exit and run!