Dash icons Not Showing properly in Menu Using WordPress

If you want to add Dashicons on WordPress frontend, you will need to enqueue them using PHP code in your theme functions.php file:

/* Add Dashicons in WordPress Front-end */
add_action( 'wp_enqueue_scripts', 'load_dashicons_front_end' );
function load_dashicons_front_end() {
   wp_enqueue_style( 'dashicons' );
}

Sample :

<i class="dashicons dashicons-admin-comments"></i> 

Chose icon