codeigniter - facebook api returns null email -

i trying use hybridauth codeigniter facebook login. have set facebook app basic permissions. interested email address of user can create account in application. have checked integration , seems work. however, in response receive, either null or string(0), email. below response.

["description"]=> string(0) ""  ["firstname"]=> string(0) ""  ["lastname"]=> string(0) ""  ["gender"]=> string(0) ""  ["language"]=> null  ["age"]=> null  ["birthday"]=> null  ["birthmonth"]=> null  ["birthyear"]=> null  ["email"]=> string(0) ""  ["emailverified"]=> string(0) ""  ["phone"]=> null       ["address"]=> null ["country"]=> null  ["region"]=> string(0) ""  ["city"]=> null  ["zip"]=> null  

this data own fb id , have set public. not receive error. application asks permission email have set in scope parameter. still not email.

please help