Back Cover for your reference with the superior quality and worked perfect with your Samsung Galaxy Note 9 (Metallic Copper).
If your Samsung Galaxy Note 9 suffered an accidently dropping and scratched the surface of the back cover, worn and torn the appearance after long time using.
You may consider replacing it with a new one.
This back cover already incised the screw holes, so you do not worry about if you can assemble the other parts, precisely cutout for the function ports and the screw holes.