How to change wordpress default login.php url using nginx rewrite rules? -

i trying change wordpress default logon url http://abc/wp-login.php http://abc/backend using rewrite rule nginx not working me. please check below code.

location /backend {   rewrite ^/backend/?$ /wp-login.php break; } 

and wordpress function is:

add_action('init', 'init_login_rules' );  function init_login_rules() {      $newurl='backend';     add_rewrite_rule( $newurl.'/?$', 'wp-login.php', 'top' );  } 

please me.