Allow your affiliates to upload an invoice when they are requesting a commission payout.
As an admin, you can then view/download the invoice in the payouts tab, before paying the commission.
This feature can be set to disabled, optional, or required.
Example of invoice upload on affiliate dashboard:
Example invoice download on admin payouts section:
To get started, simply enable the “Invoices” module on the plugin settings page, and then a new “Invoices” tab will appear to customise the settings further.