dx8 help

I brought a DX8 , go into settings cannot change battery setting as it skips it why is that thank you

So I've only been flying multi-rotors for two months, self taught and flying very low and slow normally, I've had a few higher flights recently, but wasn't planning that on this flight. I'm going to be reading here about how to properly set my DX8 throttle for this quad to avoid this risky...