Sounds like the error for "wrong SMSC (SMS centre) number"?
This normally gets set correctly automatically so it's odd that it would be wrong.
Your phone is reported here as "Huawei MAR-LX2" which seems to be a P30?
You'll need to check the phone documentation/Huawei support site to see how to set the SMSC.
Also see here:
Hope this helps.
Maybe this will help?