Hello, can you assist us in such question?
For redirecting of the Customer from our Marketplace Web application to the integrated Shopify Shop (stores that have the 'accounts are required' setting enabled)
Can this sequence work?
1. New customer (not registered) collects his cart with products info (IDs and quantity) in our app from the list (the receipt of which is described in the previous step)
2. After clicking on button "Buy" in our app we offer him to register on shopify platform ( to do this use Storefront API (customerCreate) https://shopify.dev/docs/storefront-api/reference/customers/customercreate (customerCreate image)
3. After registration we create cart with Ajax API, add items to it and save. https://shopify.dev/docs/themes/ajax-api/reference/cart
4. Redirect customer to seller's store, where he will see his cart and have possibility to start payment operations.
1. Between 2nd and 3rd steps need to create customer session. To create token of customer can be used this API call: https://shopify.dev/docs/storefront-api/reference/customers/customeraccesstokencreate But need additional investiogation, if this request can be sent from another domain (from our app).
2. Not 100% sure that customer's cart of seller's shop can be filled from another domain (from our app).