I followed the video tutorials for gd.games and itch.io. My game is available on both of those sites now, but the submit button still says I have no projects that can be submitted. Any ideas?

Here's the itch.io link:

Both Hands and a Map by Sleightblind (itch.io)

Here's the gd.games link:

Both Hands and a Map | Play on gd.games

I recommend using the Itch link since the fullscreen works there. On Gd it moves the assets around and doesn't display properly.

Does this help?

If you're having trouble uploading a web build because of the 1k item limit on itch.io, make sure you have a desktop build on your jam page to act as the official submission.  And after ensuring your game page has the desktop build, if your game is smaller than 100mb, you can upload it to gd.games using the one-click export feature on GDevelop and share the link on your game jam page for people to play your game through as well.