You can use Wi-Fi as an alternative to the mobile network when establishing an internet connection. This way your smartwatch doesn't use mobile data.
Slide your finger upwards starting from the bottom of the screen.
Press the settings icon.
Press the indicator below "Wi-Fi" to turn on the function.
Press the required Wi-Fi network.
Key in the password for the Wi-Fi network and press the confirm icon.
Press the Home key to return to the home screen.