Sorry this service is not available - Text error message

All of a sudden the other day when trying to send a text message from my iPhone 6 to my daughter’s iPhone 11 I received the following error message: “sorry this service is not available”. My iPhone 6 able to send text messages to everyone else without any problems and her iPhone 11 is able to receives text messages from all other phones with any problems. We’re both connected to wi-fi and cellular, in fact we were in the same room while trying to troubleshoot this problem. The problem came on suddenly, it’s not a group message and we’ve never experienced this problem prior to Fri. 02/07/20.

I’ve already reviewed the Apple message troubleshoot article and it doesn’t address or solve this specific issue. If the Apple community is unable to guide me then I’ll contact a apple directly.

Thank you