You cannot pay for your stay in instalments: Travelski does not offer payment in 3, 5 or 10 instalments without fees. It is not a payment option that exists at Travelski.
The two payment terms that exist
There are only 2 payment terms:
with "Flex", a first payment, then a top-up to reach the deposit, then a balance, if the booking is made more than 80 days before the start of the stay;
with "Fixe", full payment when you book, because the stay is then non-cancellable and non-refundable.
No intermediate or staggered payments
Travelski does not allow intermediate, staggered or other payments outside the due dates set out in the booking confirmation. For example, you cannot ask to pay an amount every month to spread out your balance payment.