It's our pleasure to have you back in the thread, @T190. I appreciate you for giving us further details about your payment platform.

It would be convenient for you to include a link to your payment platform in the email messages that facilitate invoices in QuickBooks Online. Your payment platform, however, is not integrated with QBO. I would suggest contacting their support to see if they have a feature that allows you to insert a hyperlink to invoices. They may be able to provide you with additional information about Easy Payments Plus.

You may want to check this article to know how to use QuickBooks Apps in the future: How to use QuickBooks Apps.

Please let me know if you have further questions about managing payments or invoices in QuickBooks Online. I'm always willing to help. Have a wonderful day!