Create a routing domain for a custom storefront
You can create a routing domain that points to a target, but that doesn't redirect to the primary domain. Routing domains are only used for custom storefronts.
To create a routing domain, you need to add a custom domain to your store.
From your Shopify admin, go to Settings > Domains.
Click the domain that you want to make a routing domain.
Click Change domain type.
Select Routing domain, and then click Change domain type.