In order to access this room you will have to play as Caustic or Wattson and go to Caustic Treatment. Move to the back of the POI and look for the two runways in search of the highest vent that will allow you to jump and climb. Then you will have to open the door of that room, always keeping the attention that there are no other players nearby who can kill you.
In this sense, we recommend putting gas in the room.
Accessing the terminal will allow you to access the backstory of Caustic's experiments and his relationship with Wattson, as well as being able to drain toxic chemicals from the ground, which will allow you to obtain 4 additional cylinders in the main chamber and also access to 4 Gold level items.
That's all you need to know about how to access the caustic treatment room at Apex Legends, and now that you know, we hope you can find it and access it smoothly to move forward with this event.