my engine ( as far as i know ) cant export to a git page

you would be hard pressed to not be able to host a codebase on github. 

If you state the name/URL of the engine you are using, someone may be able to suggest how you can do so, if it’s possible.

Also, note that–as I understand it–the intention for this jam is that you will need to upload:

• (A) your project’s source files (e.g. source code, raw assets, etc) to a GitHub repository,
• in addition to also uploading to your itch.io project page (B) the game’s Windows binary executable and/or web “export”.

In the interests of clarity, note also that:

1. The meaning of the term “export” may vary from engine to engine; and,
2. The term “GitHub repository” does not mean the same thing as a “GitHub Page”.

Edit: The replies in this thread might also be informative: https://itch.io/post/9443843