The SMS center area is good, why can't I check it? I can't send text messages either.

How to set the number of Apple SMS Center:

Enter * 55 * 7672 *+86138ABCD 5 # in the dialing interface (the+key can be entered by pressing for a long time), pause for a few seconds, and then tap the "Dial" key. After the setting is completed, you will see the prompt "Service Center address is successfully set without address", which will take effect after restarting. ABCD is the local area code. If the area code is three digits, the last digit is filled with . (Example: Shanghai 21, SMS center number is+86138215; Zhengzhou, Henan 371, SMS center number is +861383715)