Keep getting an error trying to buy Apple Care for iPhone 13 Pro

Wondering if other people are having this problem.

When I try to buy Apple Care for my new iPhone 13 Pro, I come to a screen which says "This device is eligible for an Apple Care product". So, I select it, and then on the next screen I see an error that says "Apple care products for this device are not available".

It's a brand new iPhone 13 Pro, bought in the Apple Store last week. Has anyone else had this problem?