It's nice to have you here today, @blujay22,
I can give you the steps to link a payment check to an open bill.
First, let's update the posting account of the check from Expense to Accounts Payable. Perform the steps below:
After that, you can now pay the Bill. Here's how:
That should complete your work. You can also check out this article for other options on how to handle check payments for an existing bill: Bill shows as unpaid after writing a check.
Feel free to get back to me if you have other questions about QuickBooks. I'll be more than happy to help you anytime. Have a nice day!