If you mean recording bill payment in QuickBooks Online (QBO), I'll show you the whole process below:
First, you'll want to enter a bill:
Go to the + New icon.
Select Purchase Bill.
Fill in the necessary information.
If you plan to bill a customer for the expense, select the Billable checkbox and enter their name in the Customer field.
When you're done, select Save and close.
Then, you can pay the bills. If you use a credit card or cash when paying it, you use the Pay Bills option. Do this by clicking the + New icon and choose Pay Bills.
If you use a cheque, then you'll want to record it as Cheque.
Here's how:
Go to + New.
Select Cheque.
Fill in the necessary information.
When you're done, select Save and new or Save and close.