Thanks for looping in this thread, @nch1870. I'm happy to provide you with more information about Payment processing applications, as well as a place where you can find an alternative product that you can integrate with us. 

To be eligible for a QuickBooks Payments account, you must meet certain criteria, undergo a credit check, and have your application approved. Some reasons for rejection include the types of products or services you sell, being in a high-risk industry, and the credit history of the primary account owner of QuickBooks Payments.

Learn more about the platform and its prohibition by reviewing the Merchant Agreement and Acceptable Use Policy. 

Since you're interested in exploring other products, visit this page: Apps for QuickBooks Desktop. From there, you can read user reviews and compare them to help you decide which suits your needs.

Feel free to contact our experts from the Payments Support Team for further questions. They are open from 6 A.M. to 6 P.M Pacific Time from Mondays to Fridays.

With this information, you should be able to narrow the possible reasons why the application for Payment processing is declined. This will also help you figure out the available alternatives you can consider. If there's anything else you need, let me know. Goodbye for now.