How does the iphone use the secondary card to send messages?

How to send messages using an iphone secondary card:

1. Open the phone, find the SMS icon on the phone desktop, and click Enter.

2. In the SMS interface, find the new icon in the upper right corner and click Enter.

3. In the new SMS interface, click the button on the right to add a contact.

4. In the contact interface, find the contact person who needs information.

5. After that, find the main number icon below the contact and click Enter.

6. In the pop-up dialog box, select the secondary symbol.

Precautions:

1, the main card and the auxiliary card can be switched at will.

2. Card number switching is only applicable to single SMS sending.