Help! How do i add a system mod to simplerockets2?

I download them but nothing is ever added i added over 100 and only 2-3 are actually working! I'm starting to think some of the files should not be 1mb in size like a new system the default is 4mb if i made a system that was 3 times the size i would expect the file size to be at least the same or greater then the default but no when i download them everything is 1mb except for 3 files that actually work! I have been at this all day long. I'll go to sleep and try again in the morning thank you for reponding!

To download a craft, if you are playing on steam, go into the game and in the side menu press the blue button on top that says “download crafts”. Then, pick a craft on the website and just press “download”. For systems it is pretty much the same thing and to use the system create a new sandbox and choose that system. Mods are a little more complicated. There are instructions on some mod posts that could help you. On android/iOS, you also just press the download crafts button for crafts and systems and follow the same process as on steam, but mods are not available on mobile. It sounds sort of confusing the way I worded it but once you find the download crafts button it should be pretty easy.