Show my caller ID

If your carrier allows it, it’s generally located in Settings -> Phone.

If they don’t allow it to be managed by your device, … it may be configurable “on net”

w/ touch-tone commands. (e.g. by dialing *nn)

Or it may be configurable from the account management screens of your carrier’s web site or iPhone app.

What did you carrier say? If they manage it, they either manage it and will allow it or they do not allow it. You need to ask them if they will turn it off. If they say no, then you cannot turn it off.

Contact your cellular carrier. Not all carriers support managing that setting from the settings app on the phone.

You're welcome.