Can't add my recruiter

General
#1

I’m level 12 and I can’t figure out how to add my recruiteer since here in that webpage linke down there says
“Recrutees can now set their recruiters up to level 15 (was level 5 previously)”
I saw in -can’t find out were- that you just have to add him to friends and right click “set to recruiter” but i’m not showed that option.