How to export?

Heyy, me and my friends are facing a huge problem lately: We cannot send our project to one another and so we are tied up to work on one PC. We tried everything but either Unity says the path is invalid or the projects are empty.
Plsss help

Use a Git repo, to push on your Unity project folder.
Your friend will be able to clone the repo on his computer, nad you will be able to work each on your side.