What is the problem?
When creating a new purchase invoice, you need to report and account for leasing expenses.
How to solve
1. Activate line invoicing to different accounts
Create a purchase invoice as explained here
Click on Options
Activate Account per item and Show all accounts
2. Add lease instalments and interest
Go back to the purchase invoice creation mode.
In the Item field, type in Leasing instalment and indicate the accounting account 524.
Click on Add line
Write another Concept for the interest and select the accounting account 6623.
Afterwards, when you receive the charge in the bank, you will have to reconcile it against the purchase invoice. Don't forget to modify the accounting accounts for the instalment and the interest.