This also applies to the Pro 14 and Pro 26, as well as the Scarlett 6i6, 18i8 and Clarett 2Pre and 4Pre
The Pro 24's wall adaptor automatically switches to work at any voltage in the range of: 100 - 240 V 50/60 Hz based on the voltage that it senses. If using your Pro 24 with a different supply voltage, you can simply use the plug adaptor on the wall adaptor specific to your country to connect it to the power supply. There is no need to buy a new power adaptor.
Please note that it is not advisable to purchase a Pro 24/Pro 24 DSP from a country other than your own since the warranty will reside in the country of purchase only, as explained in the warranty statement that can be viewed here.