It is not yet possible to download invoices directly from the app for Shopify stores. The charges are billed by Shopify and they should be aggregated to all your other payments in your monthly invoice. If you have any questions regarding invoicing, please contact support.
To download an invoice for your Product Recommendation Quiz, go to your app Dashboard -> Plans & Pricing. In the top right corner, you’ll see the Invoices tab.
Once you click the Invoices tab, a new page will appear with a list of all your payments.
To download the invoice, click the ‘download PDF’ option.