There are two ways to create orders to your sales channel.
Using the Checkout API
Using the Checkout API, your app can programmatically create a Shopify cart, reserve inventory, retrieve shipping rates, calculate taxes and process payments for a Shopify merchant. This API helps your channel respect the merchant's business settings and make it easy for new merchants to start selling through your app.
Using cart permalinks
All Shopify stores come with a beautiful, responsive web checkout. Cart permalinks allow you to link to a pre-filled web checkout containing product variants of your choosing. You can make sure that the resulting checkout will be attributed to your application by adding the
api_key URL parameter to the cart permalink. For cart permalinks,
api_key is a valid Public Access Token.
You can pass other marketing attribution data to Shopify using
utm URL parameters. Learn more.