In the app, when your customers buy products in installments, they do the initial payment in the amount set by you (from 0 to 99%). As for the remaining amount, the app will create draft orders and send your customers invoices according to the payment schedule.
In order to ensure that customers will get invoices, go from your Shopify admin to Settings > Checkout. In the Customer contact section, select Customers can only check out using email and click Save.
Installment payment statuses
The following statuses are available for installment payments in the app:
Pending – Order has not been paid yet.
Partially Paid – Order has been partially paid.
Canceled – Order has been canceled in the App or in the Shopify admin. In the App, you can cancel the order while it has Pending status.
Paid – All orders have been successfully paid or manually marked as paid from the Shopify admin.