The project still uses the test token the Smootify app created; use the public token of your Headless storefront.
The symptom. Orders arrive in Shopify, but customers never get the confirmation email.
Why. When the Smootify app connects, it creates a token so the site reads your products right away. It is meant for building: orders placed with it send no confirmation email.
The fix. In Shopify, create a storefront in the Headless channel, turn on all its Storefront API permissions, and put its public token in your Smootify project. Then place a test order: the email arrives, and the order shows your Headless storefront as its sales channel.