Once your payment goes through, we send an email with your invoice to your account's email address. If you search your inbox for Narrative or Stripe it should show up.
However, if you are unable to find it, please start a chat with our Support team (there's a chat window at the bottom right).
If you want to add more details to show on your invoice, you can enter them in the Billing address details in your account portal: https://account.narrative.so/subscriptions