When to Post Demo to Itch?

How do you know when your demo is ready to be published on Itch.io as a web demo?

My game is definitely not ready for a Steam demo (also no capsule art, trailer, etc.), but how do I know if it is ready to be uploaded to Itch? I had some friends play it and they said they enjoyed it, but I am not really sure if it is actually fun enough to continue working on.

It is my first game, and I am not sure when I should do each step.