Good day, @Anh5050,
Allow me to join this thread and clarify this for you.
There isn't a need to make an adjustment for your entries since the payment doesn't affect your 2018 Balance Sheet. The payment of your bill dated October 2018 is posted this year.
You can always check your Accounts Payable on your Balance Sheet report for your bills before and after making a payment.
To learn more about making and paying bills, please check out to this: How to enter and pay bills.
Don't hesitate to post again if you have a follow-up question. We're always around here in the Intuit Community whenever you need help. Have a great day ahead!
