Same thing here as Barragan.
It's also the first mod I ever used, so nothing I could have messed up before. It's on 1.6 and I spotted something loading from JSI on the loading screen so the install should be alright.
This is my file path: D:\SteamLibrary_HDD\steamapps\common\Kerbal Space Program\GameData\JSI - along with the folder 'Squad' which is also in GameData.
Also I checked at least for the pods where I could definitely match file names, namely cupola and mk3. These are correct.
Edit: Using Windows 10