To manage your billing details, head to your account page and click "Billing Dashboard": https://app.helloaudio.fm/account
This takes you to an external Stripe page where you can change your plan, add a new payment method, and download invoices.
If you'd like your address and tax ID included on the invoices, update your billing information. EU users can include their VAT ID, for example.
Click on a date in your Billing History to view the receipt and/or invoice.