Add payment method title to WooCommerce admin email

/**
 * Add payment method to WooCommerce admin email.
 */
add_action( 'woocommerce_email_after_order_table', function ( $order, $is_admin_email ) {
	if ( $is_admin_email ) {
		echo '<p><strong>Payment Method:</strong> ' . $order->payment_method_title . '</p>';
	}
}, 15, 2 );