Thanks for the question! That’s a good one and others were probably wondering the same thing. Generally the cube that comes with your charger, and definitely in the case of iphones, is dual voltage, which means it can be used with the 220 electrical current here in Bolivia. If you don’t have a dual voltage cube we can loan you one here so no need to bring any extra converters, etc. (you can check the voltage rage in fine print on your chargers).
Similarly, the outlets in Bolivia can accommodate a two-prong US charger, so you don’t need an adapter.
Hope that helps!