The real Scratch has the membership cat ears available for everyone, but this version doesn't have it…
Also, RIP:

While I'm personally not a fan of the cat ears, I do have to agree that them being missing are an inaccuracy compared to the real Scratch website. I may add them eventually, it really shouldn't be hard, though right now my priority is to improve form validation. I also need to update the footer to match the current one, I don't think I ever updated the frontend code past like January of this year or something.

Scratch Addons

Added in upstream, will close this after the website receives the update

It's been merged into my fork, however you must choose a 2026 theme for cat ears to be available seems.