tf_generic_bomb not spawning in

Basically I'm trying to spawn in tf_generic_bomb, but when I compile and run the map it doesn't show up, I think it's because it just spawns in on detonate not actually when the map starts, so if someone could tell me how to do that, or if you think it's something else and tell me what you think it is and how to fix it that would be nice, thanks in advance.