For what i understand , you want to use a new domain and to redirect to the excising website. For that you need to go to Setting-Domain and then add excising domain and connect automatically then will take you to Godady account and will automatically setting up.
For any question or query please do not hesitate to contact us on: AHTseoopt@gmail.com
I actually have an existing Domain, but I wanted to add a Subdomain.
I tried following Shopify’s directions to set it up, but I ran into an issue in GoDaddy and was wondering if anyone had this issue or if I’m doing something wrong.