Anker’s travel charger works in almost any country and is down to $20.

99 ($6 off) at Amazon, Best Buy, and directly from Anker (with code WS7DV2BNB82J) matching its best price to date. 99 at Anker (with code WS7DV2V9Q3TQ)
The Nano’s four built-in sets of prongs should keep you covered in “over 200 countries and regions,” according to Anker. It also features two USB-C ports and two USB-A ports, along with an AC outlet for plugging in a standard wall charger. Just keep in mind that the Nano doesn’t convert voltage, so you’ll want to make sure gadgets like hair dryers and electric razors support the voltage at your destination before plugging them in. 99 $19.