If you want a Vue 3 Plugin then I suggest trying vue-auth0-plugin:
npm vue-auth0-plugin
It is based on the Auth0-spa-sdk, plugs in nicely and seems to work well. I asked for a minor change, and it was implemented within 48 hours, so a responsive maintainer too.
I have written a sample app - just to try it out, if you need an example of it in use. It is a bit rough and ready, but might be useful, so I made it public.