See:
Thus:
- In chart of accounts create a Interest on Loans expense account.
- The create a Payment from your chosen bank or cash account and add 2 line items, one where account is
Bank loan
and the otherInterest payment on loans
see screenshot
So this will reduce the amount under the Assets Bank/Cash and Liabilities Bank Loan to whatever amount you decided to repay and add in this case 50,000 to the Expense account Interest payment on loans.