Cannot buy AppleCare+ for my refurbished iPhone?

Within the last week I bought a certified pre owned iphone 13 pro from Verizon, and I wanted to buy apple care+ just to insure it. But when I make any attempt to buy the service apple says my device isn't eligible. I've had the phone for less than a week and it wasn't bought from a 3rd party service, so I'm unsure what to do.

[Re-Titled by Moderator]