First, ensure your device’s software is updated. Then, follow these general steps:

• iPhone: Go to Settings > Mobile Data > Mobile Data Options > Voice & Data and select LTE, VoLTE On.

• Samsung: Go to Settings > Connections > Mobile networks and toggle the VoLTE calls switch to ON.

• Huawei/Other Android: Go to Settings > Mobile network > Mobile data and enable the VoLTE calls option.