Hello there, @gokeyandmarkle.
Let me help you post the payment to your QuickBooks Online.
Still, by following the standard procedure, we can record a bill payment to an open bill. Here's how:
- Select Expenses from the left panel.
- Navigate to the Vendors section.
- Simply click on the vendor's name.
- Select the Transactions tab.
- Make a payment on the open bill by searching for it.
- Select the bank under Bank/Credit Account.
- Remove the check mark next to Print later in the right corner.
- Enter something in the Ref no. field to help you identify the payment method (ex. ACH).
- Complete the required fields and click Save and close the window.

For more information on recording the bill payment made through ACH, you can visit the article I recommend on this: Record a bill payment processed online, via EFT, ATM, or debit card.
If you're using QuickBooks payments, typically it takes 1-5 business days to process, depending on the financial networks involved. Customers that are new to QuickBooks Payments and have an active account are eligible for next-day ACH deposits.
For other concerns, please reply again to this thread. Take care always.