Help with jigsaw structures.

Hello, I'm trying to make a dungeon. I'm going to use commands to place the structure so it's not going to need to be generated in world. I've done everything that I can think of to make this work, but it's not working. I basically copied the ancient city and changed some variables, but the structure does not show up in the /place structure list. I have other structures in there that I have done before, but they are not jigsaws. The structures that make up the jigsaws are available to place, I just cant place the actual structure that starts the dungeon. Also, this is in 1.20.1. Please help!