Firstly you want to restart the game until you hear the phone ringing

The reason why you need this to happen is that when the phone rings it lets you pass the barrier of which closes your door.

After passing the barrier that closes your door without your door closing

Grab the bucket and return to the room you were just in.

Enter your office with the bucket and close the door.

Congrats you have just achieved the office bucket ending thing.

If this guide was good at all reward if u want idrc