To load promotional message via shortcode

Instruction to load a promotional message using shortcode.

// Shortcode: [awdr_promotional_message]
add_shortcode('awdr_promotional_message', function() {
    ob_start();
    if(class_exists('Wdr\App\Router') && isset(Wdr\App\Router::$manage_discount) && method_exists(Wdr\App\Router::$manage_discount, 'displayPromotionMessages') ) {
        Wdr\App\Router::$manage_discount->displayPromotionMessages();
    }
    return ob_get_clean();
});