No, there are no fees or penalties for prepayment.
To make an early repayment, go to My Loans > Loan Details > Repayment Schedule, as on the screenshot below. Click on Repay Early if you want to make full repayment.
Whether you decide to repay the loan early or stick to the set loan schedule, the loan principal must always be repaid in full.
Here's how you repay interest:
Go to My loans, choose your loan and click on Repay button.
Choose Full Early Repayment
Pick the option you want to use to repay a loan (in loan currency, use loan collateral, or in other asset).