Popup not working

[Sbrjt]

I'm trying to convert this extension into a userscript.

I first tried with the MV3 build of the extension but the userscript didn't work. Is MV3 not supported yet?

When I used the MV2 build, most core functionality seems to work, but the popup UI and options page do not open:

Scripts I ran:

npx wxt build --mv2 (in my repo)
npx to-userscript convert .output\chrome-mv2 

Can you please take a look?