Please note only open source projects compatible with GPLv3 can use a free license. Your project should be public and accessible for anyone who want to see its code.
Usually a public repository has a website that links to the repository. Other times it is linked in the code itself.
Help us too! Instead of getting a free license you can get a commercial license quite cheap. It is a one time purchase and it can be used in multiple projects as long as they are not SaaS/OEM sites.