How to turn on the HD call settings?

The way to open the HD call settings is as follows:

Tools: Huawei p50, HarmonyOS3.0, Settings, iPhone 13, IOS 15.6, Settings.

1. Enter the Huawei mobile phone setting interface, find the mobile network in the setting interface, and click Enter.

2. After switching to the mobile network interface, find the mobile data option and click Enter.

3. After going to the mobile data page, turn on the switch button behind the VoLTE HD call.

4. In the SMS interface of Apple's mobile phone, find all the messages in the top position and click Enter.

5. After switching to the information interface, find the icon with a pen in the upper right corner and click Enter.

6. After jumping to the new message interface, enter the recipient here. Take China Mobile as an example, enter 10086, and enter KTVOLTE at a lower position to start the HD call.