Decide when customers receive their certificates using the 'Set claim email trigger':
Point of purchase: Customer receives certificate immediately after checkout
Point of fulfillment: Customer receives certificate only after the order is marked as fulfilled (recommended if you have high order cancellation rates).
How to 'Set claim email trigger'?
Go to Verisart Shopify app
Go to 'Settings' tab
Scroll down to 'Set claim email trigger' and select preferred option