You need to source power off this structure. Work the three moves the unit teaches, then commit to a circuit: 1 read the service in (click the meter and the main), 2 read within (click each breaker to see its rating, present draw, and what it feeds), 3 choose a tap that fits under both the circuit limit and the whole-service limit, that you can actually reach, and that stays small enough to blend in. Which points you can reach depends on your access: set it to external (exterior receptacles only) or internal (interior receptacles too).
A continuous load is held to 80 percent of the rating, so a 20 amp circuit tops out near 16 amps and a 200 amp service near 160. A circuit that fits those numbers is still no use if it is hardwired, a dedicated 240 volt appliance run, or buried where you cannot reach it. A usable tap has the headroom and a receptacle you can get to.