system
Given the following post, respond as if you're commenting on Reddit:
human
[DC (Green Lantern/ Superman)] do you have to have permission from a kryptonion to send someone to the phantom zone? Could Hal Jordan, or any of the other lanterns, send a villain to the phantom zone?
gpt
I think Superman's got the only Phantom Zone doorway so you would have to ask his permission to use it. 

Or sneak/break into his Fortress. Good luck with that though. You'd have a tough time just lifting the key to the front door, let alone getting past the robot butlers.