Do I set the deposit myself?

Not quite. You suggest an amount when you declare the aircraft, but it is only an estimate. During the review, Volara aligns the deposit with the actual excess on your policy, as read from your insurance certificate.

You no longer enter the excess

This field has deliberately been removed from the form. The excess is the deductible on your own policy: Volara reads it from your documents rather than having you copy it in. The deposit is then set to this figure: deposit equals excess.

Why this approach

It is the fairest option for both sides. The renter is never held for more than they could actually owe, and you are covered down to the last cent of your excess. Nobody relies on a rough estimate.