There are several solutions to access iMessage on non-Apple platforms including https://bluebubbles.app/ https://bluebubbles.app/, https://airmessage.org/ https

There are several solutions to access iMessage on non-Apple platforms including https://bluebubbles.app/ https://bluebubbles.app/, https://airmessage.org/ https://airmessage.org/, and https://www.beeper.com/ https://www.beeper.com/. You'll need an Apple device or Hackintosh as a server, but you can pay beeper to set up their software on a jailbroken iPhone and send it to you.