The general search has been changed from an exact search to a keyword search.

Announcing a Full Code Rewrite of Advanced Library Search.
Migrate to Manifest V3 and add host permissions for favicons.
The source code remains publicly available on GitHub.

Make it searchable in the address bar.
If you add it as a bookmark as follows, it can be used as a search engine.
moz-extension://ADDON-ID/index.html?t=b&q=%s

I received an email from Mozilla. They said, "You're add-on will be disabled on cup.aihedy.com in 14 days
because build process aborted with errors" But I think the build procedure performed is wrong.
I'm not sure, but I uploaded the revised version.

Postscript:
The previous version seems to have been approved by Add-ons Review Team.