Question about Mifcom SAVAGE RTX2080Ti Core i7 Advanced

Just look on the housing of the PSU to see what voltages are written there. Or look up the model name of the PSU and then check it on the manufacturer's website. You can find this informations on the back where you plug in the power cord or you have to open the sidepanel of the pc case to look on the PSU case.

Theory: The PSU transforms AC to DC, it does not matter how much AC comes into the PSU as long as the plug is able to deliver around 820 Watt. The PSU is a certified 80 Gold 650 W one, so you lose a maximum of 20% as thermic waste, which leaves your PSU with around 650 Watt capacity.
Reality: Usually european PSUs (and most other devices who transform AC to DC) are rated 110-240 Volt, whilst USofA devices are only rated 110 Volt as this is cheaper to build. I am almost sure this 110-240 Volt scenario is the case with the PSU you have.
But it might be, that you have a switch on the PSU at the back of your PC where you can choose 120 or 240. Modern devices switch themself tho. There should be a sticker on your actual PSU showing the usual data like max. Watt (650), exact voltages (either 110-240, or 240 only), manufacturer (Corsair), SN and so on. It is possible that this sticker is not visible on the installed PSU tho.
Worst Case: Your PC will not break when you plug it in, as it is built for 240 Volt, the worst that could happen is the PC won't start due to underpower.
If it doesen't work, you need to change the PSU to a USofA one.