Hook um_form_official_classes__hook

um_form_official_classes__hook.php

<?php

/**
 * Hook: um_form_official_classes__hook
 *
 * Type: filter
 *
 * Description: Change official form classes.
 *
 * @example https://github.com/ultimatemember/ultimatemember/blob/master/includes/core/class-shortcodes.php#L349
 * @link    https://docs.ultimatemember.com/article/1135-umformofficialclasseshook
 *
 * @package um\core
 * @see     um\core\Shortcodes::get_class()
 * @since   2.0
 * @version 3.0
 *
 * @param string $classes Classes string.
 *
 * @return string Classes string.
 */
function my_form_official_classes( $classes ) {
	// your code here.
	return $classes;
}
add_filter( 'um_form_official_classes__hook', 'my_form_official_classes', 10, 1 );