@Edent I don't think the built-in SIP client is universal to all Android phones 🙁My Umdigi Power3 claims to be stock Android 10 and the options to add another Calling Account are missing. The Google's help page seems to suggest this phone isn't stock Android (idk how it knows!) , so 🤷‍♀️ people's milage may vary even on phones appearing to be stock Android.https://support.google.com/phoneapp/answer/2811843?hl=en-GB Make calls over Wi-Fi - Phone app Help