Shopfy support confirmed that it’s not possible to setup a sub-domain to point directly to a collection, but suggested I could potentially setup a redirect on a subdomain within my host to point to yourmaindomain.com/collection.
Shopfy support confirmed that it’s not possible to setup a sub-domain to point directly to a collection, but suggested I could potentially setup a redirect on a subdomain within my host to point to yourmaindomain.com/collection.