I am using windows lumia 521 ,I am not getting gmail nitifications?

[Windows Central Question]

I am using windows lumia 521 ,I am not getting gmail notifications.
I tried setting _lock screen__notification_choose apps to show quick status_ but in that i cant get gmail menu _ i got only 1.none
2.games
3.messaging
4.nokia music
5. outlook
6.phone
7.whatsapp

please help me how to got gmail notification . i got message,whats app,phone.but gmail not gmail notification