Campaign Creations

My question is, how can I add new units with FireGraft to be selectable in Gateway for example? I tried a lot of things but stuff don't show up 

Aren't those things fixed? I may not remember correctly, but I think it only lets you replace units' slots, not add new ones. Might be mistaken, though.

Are you using a compatible version of starcraft with firegraft? last time I checked like 1.14 or 1.15.0 was the last version that worked with it (ya adun is hella lazy and *busy*)

I tried my mod with starcraft 1.14 and 1.15 and 1.16 too, but didn't work  Masters of Holocaust mod also has FireGraft patch in it but it's not working too 

If other mods are not working, then the problem is something with your system. What exactly do you mean by, "not working"? Does it not load at all, loads but looks like normal SC, or loads and has changes but those changes don't work as expected?

Play the mod on the version it was made with, or just wait for the new version of Firegraft.