How to use t phone as default phone on iPhone

I'd like to use T phone as my basic phone on my iPhone.

When you make and answer calls, you can only use the iPhone basic phone.

How can I change the settings?

1861 2019-02-17 Gentleman

popular How can I resolve TLS security configuration errors?

popular Is hair spray not allowed on the plane at all?

popular What are the side effects of oats?

popular Can I listen to music with Bluetooth earphones on the plane?

popular Why does it say that your license has expired on your phone?

Same Tag ios16 Public Beta Launch Schedule

Same Tag What app should I use to see the pdf on my iPhone?

Same Tag The direct purchase iPhone of the same model sold in Korea cannot be sold secondhand, right?

Same Tag Do you have any iPhone videos other than iTunes when you move them to PC?

Same Tag If I replace the iPhone battery, will it be refurbished?

Same Time Is there a solution to the problem of missing clipboard contents on iPhone?

Same Time How to use t phone as default phone on iPhone

Same Time Is there any foundation that lasts long?