Assisted dialing allows the phone to automatically assign global dialing settings for example +91 for India (IN). Once enable the assisted dialing auto Country Global code will add while making a call.
Setting path:
Assisted dialing feature is on by default. You can choose to turn it off.
To enable the option please follow the below step
Open the Phone app > Tap More options > Setting > Assisted Dialing > Turn assisted dialing on or off.
Optional: You can change the default Country code manually by tapping on “Default home Country” and select the country code
Note: Assisted dialing predicts and adds a country code when you call while traveling abroad.