The camera has an f1.7 lens, not very fast. (Not at all fast enough for low-light shots.) I suspect that the pictures you're looking at have been well-lighted by auxiliary lights, so that they're not low-light shots.
Cellphones aren't made for shooting in low light. If you want that, get a camera with a full size sensor, a lens with a large aperture and a high ISO. If you want to take pictures of concerts at night with a cellphone, shoot at high ISO (or EV or compensation [but watch the noise]) and shot a well-lit area of the stage.
(And flash will do you no good at all - most camera flashes work out to about 10 feet, and the inverse square law applies - so if the stage is 30 feet away, your flash does nothing but get you thrown out. And it the stage is more than 10 feet wide, you can't cover the whole stage with a flash. (A half-dozen large auxiliary flashes, set off by your flash, would work, but you can only do that if you're working for the band or the venue.)