I found this code and I want to know how do we add percentage discount instead of a fixed amount to the code below? I am looking to give percentage discount instead of fixed amount for minimum quantity 5 for a product category.

    function action_woocommerce_cart_calculate_fees( $cart ) {
        if ( is_admin() && ! defined( 'DOING_AJAX' ) )
            return;
    
        /* SETTINGS */
    
        // Specific categories
        $specific_categories = array( 'glitter-sticker' );
    
        // Discount
        $discount = 10;
        
        // Min quantity
        $minimun_quantity = 5;
    
        /* END SETTINGS */
        
        // Counter
        $current_quantity = 0;
    
        // Loop though each cart item
        foreach ( $cart->get_cart() as $cart_item ) {
            // Get product id
            $product_id = $cart_item['product_id'];
    
            // Has certain category     
            if ( has_term( $specific_categories, 'product_cat', $product_id ) ) {
                // Quantity
                $product_quantity = $cart_item['quantity'];
    
                // Add to total
                $current_quantity += $product_quantity;
            }
        }
    
        // Greater than or equal to
        if ( $current_quantity >= $minimun_quantity ) {          
            // Add fee
            $cart->add_fee( __( 'Discount_applied', 'woocommerce' ), -$discount, false );      
        }
    }
    add_action( 'woocommerce_cart_calculate_fees', 'action_woocommerce_cart_calculate_fees', 10, 1 );