If you want to upload videos of any Klei Entertainment game to media sharing and streaming sites (like YouTube & Twitch) you can absolutely put ads on them. All we ask is that you consider adding a link to the game's Steam page, or the game's official website on the video description. You don't have to, but it would be super awesome if you did.
You can find more info about our YouTube and Twitch video stuff in our Player Creation Guidelines.