If you closed your store and are looking to transfer the domain to another host, I recommend you to email directly to Shopify's Merchant/Technical support. They should assist you with the issue!
Contact page link: https://help.shopify.com/en/questions#/contact/email
It looks like @Nick_Marketing beat me to a response, however, he is absolutely correct.
It looks like we’ll need to access your account in order to resolve this issue. While we’re not able to provide account-specific support via the Shopify Community at this time, we’d be happy to continue assisting you through live chat, email, or callback. Please visit our Help Center Here and login to your account to create a support request. Once you explain your issue to a live support member they would be happy to walk you through the next steps of your domain transfer possibility.
Since this is the next step I've marked this reply as the solution for the benefit of others who may discover this topic. Thanks!