Web App Manifest

You might say

Check the Web App Manifest name, icons, start_url, and display, then reinstall and verify the launch result.

A JSON file that describes a Web app's name, icons, and launch behaviorA page links to this JSON file with a manifest link, and a browser can use its name, icons, start_url, and display to create an install entry and launch window. Having a Manifest does not by itself provide complete offline PWA behavior.
Manifestmanifest.json
Further reading