Where to enterPin number

I have my pin, I'm logged in as the primary account manager but under the phone tab in services I continually get this message;- "Check with the Primary Manager of this account to enter the security CPNI PIN.". I've looked at the instructions for this which refer to "go to bottom of page to the enter/change pin number" . That does not exeist at the bottom of any page I am seeing.

What is going on here?

Thanks for any enlightenment you can shed