Bought new domain, won’t register!

I purchased a new domain from Shopify and it’s still showing as available and won’t show up for me to choose in my domain selection box. Do I need to pay again to connect it to my store? If so I’ll be charged twice a year for one domain. I don’t understand why it won’t show up even though it’s been paid for?

Hello!
I made the purchase on May 9, 2025. From my debit card. It’s been over 48 hours so I’m not sure what to do next. The receipt is attached to this email if that helps.
Tyler