To set the ringing tone of the Xiaomi Smart Doorbell 3S, you can go to the [Mi Home/Xiaomi Home] APP >> select [Xiaomi Smart Doorbell 3S] >> tap the three-dot icon at the upper right corner >> [Doorbell settings] >> [Ringtone settings] >> select [Ringtone 1], [Ringtone 2] or [Ringtone 3].
Note:
The setup is completed just on the APP, and the doorbell needs to be triggered by pressing the doorbell or by someone moving before the doorbell comes online again to take effect.