Porting messages from iPhone to iPhone
How do I get my messages to go from one iPhone to the other?
iPhone X, iOS 11.2.6
Are you replacing one iPhone with another; in other words, purchasing a new iPhone to replace one you will be selling or giving away?
If so, there is a convenient way to transfer your iPhone possessions to a new one with the same Apple ID.
Otherwise, take screen shots of the messages and move those screen shots to the second iPhone.