How to change the number of iphone to send text messages?

Open Apple's mobile phone and click the information at the bottom left;

Enter the information interface and click the pen icon on the upper right;

Enter the new information interface, click the+behind the mobile phone person, and enter the address book to select friends who want to send text messages;

After selection, you can see that the main number appears in the new information interface at this time, and we click the main number;

Then, after selecting the account to be used now, click the secondary number to switch;

Next, edit the information and click Send;