Would I have to download any package for that ?
Not sure about Linux, but for MacOS and iOS, it’s an Apple requirement to use a Mac for those builds.
Isn’t it weird ? I mean why this the case ? I mean is there any reason ?
Operating systems impose their own rules for some requirements, unfortunately we have to abide by them.
But Solar2D offers a solution for that:
https://github.com/solar2d/demo-app-store-automation#solar2d–appstore-no-macos-needed