I don't think anyone makes a 240V portable air conditioner unit. Even if they did, it would not be switchable between 120V and 240V. That a feature would be very expensive to include in the product.

There are window units which require 240V. These typically units larger than 10,000 BTU.

Yes, there are portable AC units that run on 240 or 208/240. They are likely large and likely costly. Try adding "construction" to your search. You will have to sort through different chaff, but you will find them.