Greetings, @faiz-fuazi.
If you've already reconciled this transaction, then you won't be able to edit the invoice. You'll need to undo the reconciliation on that transaction to adjust the amount of the invoice.
Let's edit your invoice.
1. Go to Sales in the left-hand menu bar.
2. Select the Invoices section.
3. Choose the invoice you wish to change.
4. Adjust the information you want.
5. Click Save and Close, Save and New, or Save and Send if you need to send the invoice to a customer.
It's easy as pie.
These additional links will give you more information about invoices.
If you run into any trouble along the way, let me know. I'm only a post away if you need me. Happy Friday!
