How do I update my phone on my coverage

What coverage? If this is AppleCare then unless you have an exact replacement you have to buy a new AppleCare plan.

Click on this link to read how to 'Transfer your AppleCare plan' --> https://support.apple.com/HT202712

lashundra7913 Said:

"How do I update my phone on my coverage"

-------

AppleCare:

Looking to see if you can get these covered by AppleCare? If so, perform the following:

1. Get the Serial Number: Find the Serial Number of your Apple Product - Apple support
2. Enter the Serial Number: Check Your Service and Support Coverage - Apple Support
3. Buying the AppleCare: Buy an AppleCare Plan - Apple Support

Update your phone on what coverage? You need to fully explain what it is that you are trying to do.