You can check this app online here: https://koshka.ddns.net/pzemweb/v1.1/ (You will need Chrome browser or similar )
A web-app (web-interface) for Peacefair PZEM energy monitors.
It is loaded from https web server but works completely on a local machine with local devices and local database.
It uses Web Serial API to connect to PZEM devices and IndexedDB to store data.