Go to Settings → Billing.
Toggle on Email receipts.
With this setting is enabled, the invoice and receipt will be sent to your account email after each payment.
Team plan
For users on a team plan, the above may be sufficient. If you'd like to send invoices and receipts to a different email address than the one associated with the account, you can do the following.
Go to Settings → Team.
Add the email address you'd like to receive receipts as a Viewer. This will ensure that you're not charged for that account.
Sign in to that account on Circleback, you'll need access to the email address to receive the login code.
Navigate to Settings → Billing and toggle on Email receipts.
Once the account is created, sign in to the original Circleback account and return to Settings → Team.
Select the … next to the user you'd like to receive billing emails and select Make billing owner.
Going forward, your billing will be associated with that user and that email address will receive receipts and invoices.