QB Bill Payment is add-on and you can't use it as a stand alone app.

You can use Bill.com as a stand alone app and get rewards

https://referral.bill.com/rewards

Another option, you can use Melio as a stand alone app. It offers a free plan and you can get cashbacks.

https://quickbooks.intuit.com/learn-support/global/manage-suppliers-and-expenses/pay-bills-online/01...