TLDR: Apparently, specifically the userscript/network interception patches made it so you couldn't buy stuff from the item shop.
If you were using the ⭐ DEFAULT patch (currently hardcoded) you are unaffected by this bug.
I've also fixed the chrome extension randomly breaking patches when changed due to caching issues (used to happen rarely).

• Note 1: This will be the latest version for the foreseeable future, as the extension is feature complete 🎉
• Note 2: I recommend turning on notifications regardless of where you installed the extension since they aren't as intrusive anymore
• Note 3: I will try to maintain this extension (as in mainly fix website-breaking issues) until about March 2026 which is about ~8 months from the original release date.

Once again, thank you for your support + this is now the most popular duolingo extension on the mozilla addon store!
The fact that a patch as old as v1.0 still remains functional after several months is a great sign. 🤞🏾 Hopefully, we can maintain that stability with the patches after that as well!

This release is extremely future-proof and may last a year or longer.