Update 'site.webmanifest'

site.webmanifest

@@ -15,6 +15,6 @@
     ],
     "theme_color": "#0f4d8b",
     "background_color": "#0f4d8b",
-    "start_url": "https://canary.moosburger-ministranten.de",
+    "start_url": "https://beta.moosburger-ministranten.de",
     "display": "standalone"
 }