Ciao does not process payments between guests and hosts. That means that you need to agree and pay directly with money transfer or cash.
We highly recommend guests to leave a deposit and pay host only at arrival. This helps to avoid any issues with money. Hosts can request a deposit directly in the app when they are approving your booking request.
There's no requirement to use a deposit but it helps to keep everyone safe. Ultimately, it's guest and host to agree on what works best.