Install sing-box MT
Use sing-box MT on the App Store. Its public listing requires iOS/iPadOS 15.0 or newer. This is a US storefront link; availability depends on the account’s store. The old VT app and GitHub core tags do not identify the current store app/version. The SFI-iphoneos-arm64.deb asset is for jailbroken devices, not a normal iPhone install.
VPN authorization and profiles
Allow the system VPN configuration prompt when starting the tunnel.
A Remote URL must return compatible sing-box JSON; Local uses a local configuration. See the common guide for the fields and configuration requirements.
Select and start the saved profile, then verify access. Adding a profile alone does not establish a working connection.
After enabling the service, check its running state and actual website access. A VPN icon alone cannot confirm that the node or DNS works.
Groups are available when the configuration defines Selector or URLTest outbounds. A latency test is not an access test. See group selection in the common guide.
iOS permission and connection checks
If the system VPN request was declined, start again and follow the authorization prompt. Check which VPN configuration or app is active if another VPN affects access. If the same profile works differently over Wi-Fi and cellular, record which network fails and check routing, DNS and node reachability. The system VPN icon alone does not prove that every app uses the intended proxy; see the FAQ.