Where can I buy $500 gift cards for amazon.com with cryptocurrency?

When bitcoin topped $70,000 recently, I went to a few gift card outlet websites. But when I actually went to add a $500 gift card for amazon.com to my cart, they said it was "currently unavailable".

Did amazon.com stop selling gift cards to third parties? Or was this a temporary supply problem during the ATH?

Where can I currently buy a few $500 gift cards for amazon.com using cryptocurrency?