Hi there i was have damaged in my display and I changed the display, how can I know if the display is original or no. Thanks for your support

Apple doesn't sell/distribute original iOS devices spare parts to anyone, except to their Apple Stores or Authorized Service Providers around the world. So if you bought that screen and replaced it on your own, most likely that screen is not genuine or not new.

If you're living in the USA, you might have adhered to this self-repair program:--> Apple’s Self Service Repair now available, reading also this support article:--> Self Service Repair - Apple support

Regards

Giulio

With iOS 15.2 and later, you can go to Settings > General > About to see the parts and service history of your iPhone.

• For iPhone XR, XS, XS Max, and later, including iPhone SE (2nd generation), you can see if the battery has been replaced.
• For iPhone 11 models, you can see if the battery or display has been replaced.
• For iPhone 12 models and iPhone 13 models, you can see if the battery, display, or camera has been replaced.