Users with the role of Billing or Owner can find all previous invoices by going to the Organization dropdown (top-left) → Usage & Billing → Usage & Payments → Receipts.
Note: You must have either Billing or Owner permissions to access and/or make changes to information on this page. If you don't have those permissions, or you are not a member of the organization in Sentry, please reach out to a Billing member or an Owner to obtain invoices.