How can I disable iMessage on MacBook Pro?
as above, stop iMessage sending to MacBook Pro 2012/3; restrict messages to iPhone 14, ios 18.3
[Re-Titled by Moderator]
Original Title: Eliminate iMessage from my MacBook Pro
iPhone 14, iOS 18
Also, if you have used or plan to use iPhone Mirroring, you can turn off the notifications that your phone will send to your Mac (which otherwise would happen even if you shut off Messages on the Mac).
Manage iPhone notifications on Mac - Apple Support