Messages activation error during set up on Macbook Air

Messages works fine on my iPhone 8. I am try to set up Messages on my Macbook Air using my Apple ID. and continued to the the activation error message. I have gone through all of the set up to add my Air to my devices. I have turned on all the requirements to use my Air for messaging via WiFi. I have read the support articles and followed all instructions dilligently, several times. I turned off Messages and Facetime, restarted my iPhone and waited the many hours for both to be reactivated. Nothing works. In the support article from Apple, the next step is calling Apple Support. That costs money I don't have. Is there any work around this activation error while setting up Message on Macbook Air? Has anyone found a fix?