Yes — you can repay Credicorp Slice early at any time, with no penalty and no fee.
When you settle before the final instalment, the unused part of the Slice fee is refunded. The refund is calculated from the settlement date, so the sooner you settle, the more you get back.
To settle early, sign in to the customer portal, open your Slice agreement, and choose "Settle in full now". The portal shows the exact amount needed on the date you pick.
See also: How much does Credicorp Slice cost?, Can I use Slice more than once?, Slice glossary: instalment.