To gain Shopify partner access to your eCommerce site, we’ll issue a request for access from our Shopify Partner dashboard. Before doing so, we’ll need to obtain your “native” Shopify address.
That’s the address that Shopify initially assigned to your site, before it was associated with your domain name.
Usually it looks something like “domain name.myshopify.com” or “domain-name.myshopify.com. It’s shown in the Admin section when you’re logged into Shopify.