Welp, it’s not likely that the wiring was set-up to the outlets to easily allow for 240.
For the US, you could check the voltage across the two hots (the small spade terminal in the outlet). If they measure 240V, then that indicates that they have run two hots + neutral + gnd and have split the outlet to get 120V. In that case, you could replace the outlet with a 240 outlet. If it measures ~zero across the hots, then it’s not wired to make the conversion easy. Sometimes a dryer outlet will be 240V, if nearby, but I’m not certain of the gnd/neutral bond for safety.
But, it is unlikely to have 240V split on an outlet and is not a common practice because it’s expensive to wire things that way and, in most cases, unnecessary. Also, you note a small apartment, it’s not clear if they’ll run two hots (opposite phase) to a such a unit.
An electrician may have some thoughts. Other methods are a bit dangerous and won’t describe it here.
What kind of lamps?