->favicon(asset('/images/favicon.png')) in my panel. When I call my panel in the local environment, the favicon is provided and included as expected.asset('/images/favicon.png') once on my fly.io instance via SSH in artisan tinker, I also get the path including HTTPS.ASSET_URL env var. If that doesn't work try adding a force HTTPS in a service provider depending on your apps environment. https://stackoverflow.com/a/51819095