I simply transferred the required files (toi and toi.mod) into PC>Docs>Hoi4>mod. I reverted my game to 1.5.4. I see that the mod is compatible for 1.8.0 (the old launcher opened) after doing so. I then reverted it to said version however in the new launcher the mod wasn't showing up. I then subbed to the steam mod but I have to, again, revert it back to 1.5.4.

I'm starting to think that I need to use GitHub.