I created a repository introducing a usage example of Leaflet with Vue 3 (including coordinate range retrieval).
The working example is available here:
https://static.ldas.jp/vue3-leaflet/
The source code is available here:
https://github.com/ldasjp8/vue3-leaflet
As a Vue 3 beginner, there may be errors, but we hope this serves as a useful reference.