Other Ibishu pigeon camper

im trying to post this mod where i made a custom ibishu pigeon and made it into basically a campervan, i didn't make any custom parts for the vehicle because all the jbeam and everything is too complicated. but just one problem, when i drag it from files into the post resource page it just says:The uploaded file does not have an allowed extension.

 

it means that you're meant to upload a .zip file with the whole mod packaged inside.

 

I tried that earlier with a mod and it said something like an error