Do a public match and you'll sit in an empty lobby. Hit the ~ key and type xpartygo in the in-game console. The match will start. Pick a class then hit ~ again and type spawnbot 17 (or whatever # of bots you want).
I understand what to do, but when I’m in the lobby it just sits there and says “ Joining game lobby” I’ve let it sit for awhile and never changes. If you look at the picture on this post that’s exactly what it does. No map ever appears.