You can trade options only during US stock market hours, Monday through Friday. There is no extended-hours trading like some stocks offer.
Trading hours
The exact hours in your time zone appear in the app and shift with US daylight saving time. Outside market hours, you can still browse the contract list with the last prices from the session. Any order you place stays pending until the market opens again.
Currency
Options trade in US dollars (USD), the same as US stocks.
Cost
Before you confirm any order, the review screen shows the full breakdown: the premium, the commission, and the total. Nothing is charged without you seeing it first.