I'd like to share with you this snip:

{
  "short_name": "Short Site name",
  "name": "SiteName",
  "icons": [
    {
      "src": "/images/style/logo.png",
      "type": "image/png",
      "sizes": "512x512"
    }
  ],
  "start_url": "/",
  "background_color": "#495a71",
  "display": "standalone",
  "scope": "/",
  "theme_color": "#6DAEFF"
}