Exchange 2013 - delegate create mailbox

Hi

i want to give the Help-Desk team permission to only to create and delete mailbox

i used this article: 

https://technet.microsoft.com/en-us/library/dd351237(v=exchg.160).aspx

then when they connect to the "exchange admin center" url by browser. they dont see the "recipients" option like i see with my exchange admin user.

what did i did wrong?