1. Settings
L2TP is configured with Android's own tools, no app is needed. Open “Settings” and find the VPN section — its place differs between firmwares, so the easiest way is to type “VPN” into the settings search.
⚠️ On Android 12 and newer the built-in L2TP client has been removed by Google. If there is no L2TP section in the settings, use the other protocols from your subscription: V2Ray via Happ or INCY, AmneziaWG, WireGuard or IKEv2 via strongSwan — the guides are in the “Useful links” block.