Use Messages with your Mac - Apple Support
Messages is the text-messaging software included with your Mac.
Use it to send messages from iMessage or other messaging services.
//support.apple.com/en-us/HT202549
• About iMessage and SMS/MMS - Apple Support
• Add or remove your phone number in Messages or FaceTime - Apple Support
{A few people I know, ask if I could get SMS or text messages, although
my only iDevice is no longer set up~ and I don't use 'messages' in Mac.
If they want to contact me, email or a real post office box works fine.}
Not sure if you have to clear any older settings or plist item regarding
the issue you have with using your text message; or text with google.
I've turned-off options with google for text.
Perhaps someone who's had similar issue may respond.
Good luck in this matter...! 🙂