Gazelle/manifest.php

<?php
require 'classes/config.php'; ?>

{
  "name": "<?= SITE_NAME ?>",
  "short_name": "<?= SITE_NAME ?>",
  "start_url": "index.php",
  "display": "standalone",
  "background_color": "#FCC2E6",
  "theme_color": "#451740",
  "icons": [{
    "src": "static/common/icon.png",
    "sizes": "120x120",
    "type": "image/png"
  }]
}