Hey mate, in case you didnt know...
In order to enter a game made with scratch online, follow these instructions after you have set up a game page on itch:-
1. Set 'Kind of Project' to Downloadable
2. Select 'Add External File' (it's to the right of the 'Upload File' and 'Choose From Dropbox' buttons)
3. Change type from Executable to Source Code.
4. Copy and paste the Scratch URL for the game into the 'http://' section.
The 'Download' button on your new itch page will now take players directly to your browser playable Scratch game!
You can now enter your game into any game jam!