Nick here from Shopify.
Can I ask where you bought the domain from, please? If you bought it from a third party domain host such as GoDaddy then your next port of call should be to reach out to them about it. if you bought it from within the Shopify admin, can you let me know please and I can look into the best next steps for you.
Let me know!
All the best, Nick
I have sent you an email about this directly. If your any reason you didn't get an email, can you let me know in reply here please.