How to apply promo codes
From Atlassian:
Who can apply an app promo code? - Billing admins
In the improved billing experience, there are a few roles that have different levels of billing access: billing admins, business contacts, organization admins, and site administrators. Read more about billing administration
To apply a promotional code for a Marketplace app hosted on the cloud, use the following instructions:
Go to admin.atlassian.com/billing. Select your billing account if you have more than one.
Select Subscriptions from the side navigation.
In the subscriptions table, find the app you have a promo code for and select Manage.
Select More actions > Enter promo code.
Enter your promo code and select Validate.
4. Once the app is validated successfully, click on the “Apply promotion code” button.
Result: Promo code successfully applied 🎉
Read the documentation from Atlassian: Apply a promo code to an app purchase