Why I can't turn off my Caller ID in iPhone?

Caller ID is a carrier supported feature. Contact your carrier to ask that question.

Wireless carrier support and features for iPhone

https://support.apple.com/en-us/HT204039

I try to off my caller ID.. when I go to setting - phone - caller ID .. they system only running none stop .. the icon ON and OFF not appear .

how to ON ..I prefer shown my caller ID