Hi Magnus! There are a few things you can do here -

I would maybe recommend making a game submission page that acts as a dev log, includes a build that you upload, etc, and submit that to the jam. You can also make a general game page that will be intended for the final release of your game and submit that so that it is part of the jam. There's a bit more guidance here on our jam page under "How to Submit an Unfinished, Long-Term Project" if you want other details/ideas!