Credits: XLite
How to get into the Backrooms realm
First, find the Endstone and smelt it in any local furnace to get the Unidentifiable Residue. You will need 8 Residues and a Crafting table to build the Anomalous Constructor. Finally, you'll craft the Inter-Dimensional Breacher Device using the Constructor and a few decorations blocks.
After going through the Inter-Dimensional Breacher device, you will find yourself in the Backrooms. To survive this nightmare, you'll need to scavenge for 3 keys hidden across the 3 main areas of the game. However, finding these keys won't be an easy task, as they are scattered and well-hidden.
After you've collected all 3 keys, head back to the spawn area and insert them into the blue keyholes. This will allow you to escape The Backrooms and return to your regular Minecraft world. But don't rush to leave just yet - take the time to explore all of the secrets and discover new treasures, like a new Music Disc!
In addition to these challenges, you'll also encounter the menacing monsters that inhabit the realm. The infamous Twisted Redrooms are just one example of the dangers that await you. Each level offers unique challenges and rewards.
To help you navigate and survive, you'll find a useful tool called the Backrooms Computer. It allows you to purchase materials and items that may be difficult to obtain in the Backrooms. However, be careful not to use it too often, as it may attract unwanted attention from lurking monsters.