How to hide Add Friend button on Facebook

It's simple work

frist see the screenshot for WEB version

click the showing icon

click settings

 click privacy

 click edit

 click every one

 click select friends of friends

Now mobile version

this tutorial working on opera mini 

go to facebook.com

under this page go to setting & privacy

go to privacy

see 

Who can send you friend requests?                                           click hear                         then choice Friends of Friends                                           now finished