There is an undocumented endpoint to get the entries from a jam that you can find by inspecting the network panel on the submission listing page.
Example URL: https://itch.io/jam/310237/entries.json taken from https://itch.io/jam/amaze-me-game-jam/entries
Note these are the props that are used to render the UI, so we can’t make any guarantee of what will be available and in what format, but it’s unlikely to change substantially. You’re welcome to hit it with your scripts and consume it as necessary.