Thanks for reaching out to the Community, hants,
I'm here to help share information on how to record transactions in QuickBooks Online.
To start, you'll need to create a Bank Deposit to Accounts Payable and link the Deposit to the Check issued to the Vendor, so the Bill will be opened as unpaid. . Here's how:
Once done, you can re-issue the Bill Payment check again for the repayment of the bank and link the deposit.
For additional reference, check out this article: Record and Manage Bank Deposits in QuickBooks Online.
That will get you on the right track, hants. If you have any additional questions in recording your transactions, please let me know. Have a wonderful day ahead!