Hi @Zvebra, welcome to our forum!
Your question has been translated to English as this is an International forum.
Is it the number for the SMS center that you are looking for? You can find this if you open up the Messaging application > 3 dots in the top right corner > Settings > SMS center number.
Do note that in most cases you can't edit this information as it is collected from your SIM card and if you are experiencing that you can't send or receive text messages, try with a different SIM card in your device.
Let me know how it goes!
