Hello, I'm trying to submit to the jam but I'm having problems doing so, Help please, This is my first time submitting to a game jam

If you have submitted game but it is not working properly then that's fine,  usually the jam let's you change files and stuff of a submission after the deadline.

If you haven't submitted then I don't think you will be able to submit at all

Thanks for your reply

Depends if you are using WebGL or not. If so, go to Unity Edit > Project Settings > Player > WebGL Settings > Publishing Settings and set the compression format to disabled. That will work. It worked for me today. If you're not using unity WebGL, then I do not know because this is my first game jam too.