Once you've saved the account settings, the app will attempt to register with the SIP server. If the configuration is correct, you should see a "Registered" status next to your account name.

In the Settings menu, select "Account Settings" or "SIP Account" (the exact label may vary depending on the app version).

Open the Itel mobile dialer app on your device. If you don't have the app installed, you can download it from the Google Play Store or Apple App Store.

Tap on "Save" or "OK" to save the account settings.