If your Redmi Note 13 Pro is unable to send SMS messages, please refer to the following to troubleshoot the issue:
1. Ensure that your phone has a stable network connection and sufficient signal strength. Poor network coverage can prevent SMS from being sent;
2. Make sure you have enough balance to send SMS messages;
3. Make sure the number you are sending the SMS to is entered correctly;
4. You can clear the cache to see if the issue persists;
5. Please go to the Settings APP to check for updates. Ensure your device has the latest software version;
6. Restart your phone can resolve issues with sending SMS. Please try turning your phone off and on again;
7. Try using a different SIM card on your phone to see if the issue is related to your carrier or SIM card.
If none of the above solutions work, please submit feedback through your phone for further assistance.