You need to view invoices for your Heroku Personal Account or a Heroku Team.
Heroku bills on a monthly basis for usage accrued in the previous month. Here are instructions to review monthly invoices for either your Personal Heroku Account or a Heroku Team.
Note: Your Personal Heroku Account may not be accruing paid usage and display invoices. Be sure to check any Heroku Team(s) for invoices as well.
You can access invoices for your Personal Heroku Account by going to Account Settings > Billing tab. Invoices will include all apps and account features associated with the email address you're logged in with.
Heroku Teams are billed on a per Team basis. Invoices are located under the Personal menu on your Heroku Dashboard. You can view invoices by selecting the Team name from the drop-down menu, and going to the Billing tab.
If you do not seen any Team(s) listed here, then you are not a member of the team and will first need to be invited by an Admin. Invoices for Heroku Teams are are only visible to Admins and you can learn more about Team permissions here: