I've got the steps to record a loan payment with monthly interest in QuickBooks Online, Kris_Tine. 

You can record the loan payments by writing a check. I'll show you how: 

1. Click + New, then select Check. 
2. Add a check number if you plan to send an actual check. If you use direct withdrawal or an EFT, enter Debit or EFT in the Check no. field. 

Then enter the following in the Category details section of the Check: 

1. Select the account you created from the Category dropdown from the first line to track loans. 
2. On the second line, tap the expense account for the interest from the Category. Then enter the interest amount.
3. Click Save and close. 

For more information about managing loan payments, check this article (Proceed to Step 3): Make a loan payment in QuickBooks Online.  

I recommend consulting with your accountant for additional guidance regarding this matter. This way, we can ensure the accuracy of your books. If you don't have one, use our Find an Accountant tool to look in your area. 

If you need help reconciling your account, please refer to this link: Reconcile an account in QuickBooks Online. 

Let me know if you have more questions regarding recording loan payments. I got your back. Have a good one!