Take a look at your shutter speed and aperture and see if you can capture more light in the first place.
But whenever you have the choice, it’s best to avoid having the boost the ISO too high. Take a look at your shutter speed and aperture and see if you can capture more light in the first place. Maybe you’ll notice that you’ve programmed a shutter speed of 1/2000 second when you could easily get away with 1/500 second (capturing four times as many light) and a substantially lower ISO.