For anyone stuck in sending message to verify account

Here is how I successfully sent the message:

  • Download a different messaging app (I used Google Messages).
  • Set that app as your default.
  • Scan the QR code to authenticate, and you can now send the verification message.

I tried this, and it worked.

My phone doesn’t support the latest Google Play Services, so I can’t use Google Messages. Is there any other workaround or alternative messaging app that works?

you can try another mesages app, my phone is old and can not send google sms (i don’t know why, but normal sms can).