We are implementing an e-commerce app using Shopify private app, where users can list products/variants, add the products/variants to cart and trying to complete the checkout process without navigating to the Shopify Checkout page. Currently, we are using the storefront GraphQL APIs to do this (Querying, Checkout items add/remove).
I also came across a few discussions mentioning that the app should be a sales channel app and request for payment processing.
Is there any other way we can implement the custom checkout experience without creating a sales channel app?
If it is done only by using the sales channel app what are all the steps we should follow? What are the points we should consider while creating a sales channel app?
We also checked the other thread saying "The only options currently are Stripe, Spreedly, or directly with the proper PCI compliance scope." If there is any documents explaining this will be more helpful.
Looking forward to your reply.