I don't know what is included in the scope of delivery today. I bought the appliance in 2020. At that time, the cooker was complete (without a base) with connection hose to the gas cylinder, including both connection valves.
Yes, that's possible. I work with a normal camping gas bottle. Connection valve, hose and connection to the gas cooker are all included in the delivery. Just connect the bottle and the cooker is ready.