How do I turn on my phone number on my macbook in order to receive iMessages?

Go to Settings>Messages>Send & Receive, note the Apple ID, then confirm that the new number is listed and selected under "Start new conversations from" at the bottom.

Then open the Messages app on your Mac, go to Messages>Preferences>Accounts, select iMessage on the left, confirm that you are signed in with the same Apple ID as your phone, that the correct phone number is listed and selected under "You can be reached by iMessage at". If it isn't, sign out, then sign back in using the correct ID. Also confirm that "Enable this account" is checked.

I've tried this multiple times but I still can't get iMessage to turn "on-line". It just stays "offline" Any other suggestions out there?