function ng_slicknav_scripts_styles() {

  wp_register_script ( 'slickjs' , plugins_url( '/js/jquery.slicknav.min.js',  __FILE__), array( 'jquery' ), '1.0.2', false );
  wp_register_style ( 'slickcss' , plugins_url( '/css/slicknav.css',  __FILE__), '' , '1.0.2', 'all' );
  wp_register_script ( 'slickinit' , plugins_url( '/js/slicknav-init.js',  __FILE__), array( 'slickjs' ), '1.2.0', false );

  wp_enqueue_script( 'slickjs' );
  wp_enqueue_style( 'slickcss' );


  $options = get_option('ng_slicknavmenu');
  // Add PHP plugin variables to the $params[] array to pass to jQuery
  $data = array (
    'ng-slicknav-menu'         => $options['ng_slicknav_menu'],
    'ng-slicknav-position'     => $options['ng_slicknav_position'],
    'ng-slicknav-label'        => $options['ng_slicknav_label'],
    'ng-slicknav-parent-links' => $options['ng_slicknav_parent_links'],
    'ng-slicknav-speed'        => $options['ng_slicknav_speed']
  );

  // Pass PHP variables to jQuery script
  wp_localize_script( 'slickinit', 'phpVars', $data );

  wp_enqueue_script( 'slickinit' );
}

add_action( 'wp_enqueue_scripts', 'ng_slicknav_scripts_styles' );

<script type="text/javascript">
/* <![CDATA[ */
var phpVars = {"ng-slicknav-menu":"#menu-secondary-navigation","ng-slicknav-position":"body","ng-slicknav-label":"MENU","ng-slicknav-parent-links":"true","ng-slicknav-speed":"400"};
/* ]]> */
</script>

jQuery(document).ready(function($) {
            $('phpVars.ng-slicknav-menu').slicknav({
                prependTo:'phpVars.ng-slicknav-position',
                label:'phpVars.ng-slicknav-label',
                allowParentLinks: phpVars.ng_slicknav_parent_links,
                duration:phpVars.ng_slicknav_speed,
            });
            });