I am not an electrician so I can't help you get the job done. That looks like a pretty small box to me, is this an apartment? I ask because I wonder if what is feeding that small box is a breaker from another, main box. If so, you might be limited in how much amperage is available to you. First question to answer is what kind of amperage is feeding that box. Next question is how much of that is currently used in existing circuits. Next, what is the requirement for the new device, and is there enough amperage to service it? If so, then it is a fairly simple matter to install a new (double pole, if necessary) breaker to accommodate an outlet for the device. Assuming there is physical space on the board for the new breaker.