My iMessage is not working

Hello RoseJohn56,

Be sure to check and see if iMessage is activated at the moment. On iOS that can be found within Settings > Messages > Check under the iMessage on/off switch for any error text.

If it notes any alerts such as 'Waiting for activation', 'Activation unsuccessful', etc, then the steps here should be able to help resolve most issues for that: If you can’t turn on or sign in to iMessage or FaceTime - Apple Support

If you're also unable to send SMS messages (green bubbles), then there are some additional suggestions here that may help out: If you can't send or receive messages on your iPhone or iPad - Apple Support

Cheers.