iPhone display is a genuine Apple part?

Your phone will continue to work, but there’s a good chance Face ID won’t work. The message is a warning that the screen on your phone does not meet Apple’s standards, but if it works then you can continue to use it.

If it says it is not a genuine display it means that the display was not manufactured by Apple’s approved vendor to Apple’s specifications, and not installed by an Apple approved service facility. It is not a reference to the quality of the display, and if it is working perfectly there is no problem with your continuing to use it. This is all explained in the Related Article at the top of this page that you read before you clicked in the article to post in the forum.

You need to provide more information. Did you have a service done at a place other than an Apple Store or Apple authorized service center?

What is the error message that you are getting?

The screen was replaced by a service center that was not authorized by Apple. You cannot get rid of that message without having the screen replaced by Apple.

Then you will have to live with the message.

As you have been told, there is no way to get rid of the message as long as your phone does not have a genuine Apple display.