Hook um_form_fields_textarea_settings

um_form_fields_textarea_settings.php

<?php

/**
 * Hook: um_form_fields_textarea_settings
 *
 * Type: filter
 *
 * Description: Change WP Editor options for textarea init.
 *
 * @example https://github.com/ultimatemember/ultimatemember/blob/master/includes/core/class-fields.php#L2737
 * @link    https://docs.ultimatemember.com/article/1134-umformfieldstextareasettings
 *
 * @package um\core
 * @see     um\core\Fields::edit_field()
 * @since   2.0
 * @version 3.0
 *
 * @param array $textarea_settings WP Editor settings.
 *
 * @return array WP Editor settings.
 */
function my_textarea_settings( $textarea_settings ) {
	// your code here.
	return $textarea_settings;
}
add_filter( 'um_form_fields_textarea_settings', 'my_textarea_settings', 10, 1 );