Imessages

Hello vanjalica,

Thanks for posting in Apple Support Communities. We understand that you are having issues activating iMessage on your Mac.

First, make sure that your phone number and Apple ID are correct in your Message preferences using the guidance from Add or remove your phone number in Messages or FaceTime.

Next, we also recommend trying the steps from If you can't sign in to your iMessage account or FaceTime on your Mac.

Have a great day!