Apple Watch Ultra
I can't use Wi-Fi
Solution 2 of 3: No connection to a Wi-Fi network is established
You can use Wi-Fi as an alternative to the mobile network when establishing an internet connection. This way your Apple Watch doesn't use mobile data.
Press the Digital Crown.
Press the settings icon.
Press Wi-Fi.
Press the indicator next to "Wi-Fi" to turn on the function.
Press the required Wi-Fi network.
Key in the password for the Wi-Fi network and press Join.
Press the Digital Crown to return to the home screen.