I can't find the number of the SMS center there. I can't send text messages.

Don't listen to the above nonsense, open the SMS interface of the mobile phone, which has a setting, and then some mobile phone information center numbers are in its account data, and some are directly marked with information center numbers. If you don't have these options, try to see if it is not in the mode you said, open it, and an editor may be in it. If not, go to your mobile phone and ask someone else for help.