Hello, I have a question regarding admin authentication. I have a request from a client to build an app for their store but the app is actually for the storefront (online store) and not for admin. So the client does not want to integrate the app with the admin panel. He want to access the app from external link. Is it possible to sync his Shopify credentials with the external app so he can use same login credentials for both Shopify store and external app as well?