Thanks for sharing your concerns in this conversation, @KA2022. 

You can create an Accounts Payable account for the transaction and create a journal entry to post the total amount of the payment. 

Then, make another journal entry transaction to post the advance payment. 

Here's how to create an Accounts Payable account:

1. Go to the Settings menu, then select Chart of Accounts.
2. Click the New button.
3. On the Accounts type field, choose Accounts Payable.
4. Enter a descriptive name of the account to easily identify it.
5. Once done, select Save and close. You can check out the screenshot for additional reference.

Here's how to create a journal entry to post the total payable amount in the account you've just made:

1. Go to the + New button, then select Journal entry.
2. On the first line, enter the Accounts Payable you've created, then debit the total amount you've owed.
3. Enter the name of your supplier under the Name column.
4. On the second line, choose an expense account and credit the total amount.
5. Select Save and new. I've also added a sample screenshot to see what it looks like.

Then, record the Advance payment on the Accounts payable.

1. On the Journal entry page.
2. Credit the advance payment on the specific Accounts payable of your supplier.
3. Enter the name of your supplier under the Name column.
4. On the second line, debit the amount to the Bank you've used to pay.
5. Once done, select Save and close. Here's a sample screenshot for this step.

Once done, you can check out the register of the Accounts payable you've created to track the payment. 

For the monthly payment, follow Step 3 when recording. Check out this link to learn more about entering details in a journal entry in QuickBooks Online.

I've also added this article to help you categorising and matching your transactions in QuickBooks Online.

Let me know if you have any follow-up questions. I'll be around to guide you some more. Thanks again for trusting us with your business.