Let me be the first to welcome you to the Community, userrajakumar-r.
If you're trying to create a printable credit note in QuickBooks Online (QBO), right now it's unavailable. You can use the Journal entry feature instead if it is for customer expenses incurred on their behalf.
To create a journal entry, here's how:
Once the customer makes a payment, create a deposit.
However, if you're trying to create a debit note for a supplier for returning the items or for some other reason, then, use the Supplier credit option.
Here's what you'll need to do:
If the supplier pays back, enter a deposit.
For more details, take a look at this article: How to create a debit note in QuickBooks.
If you have additional concerns or any questions about debit note, let me know by adding a comment. I'm always here to help. Have a pleasant day ahead!