Ultimate Member v3: Password Reset 'um_lostpassword_form_args' hook

functions.php

// 'um_reset_password_page_hidden_fields' - use filter's hook `um_lostpassword_form_args` instead and add the hiddens to it
// 'um_after_password_reset_fields' - use filter's hook `um_lostpassword_form_args` instead and add the fields to it

/**
 * Description: Fires before rendering the lost password form and filters the lost password arguments.
 * This hook may be used to add custom hidden fields or display custom content in the password reset form header.
 *
 * Hook: um_lostpassword_form_args
 *
 * Type: filter
 *
 * @package  um\core
 * @since    3.0.0
 *
 * @param array $args Lost Password form arguments necessary for init form.
 */
function mylostpassword_form_args( $args ) {
	// default array for the arguments.
	/* $args = array(
		'id'        => 'um-lostpassword',
		'class'     => 'um-top-label um-center-always',
		'prefix_id' => '',
		'fields'    => array(
			array(
				'type'        => 'text',
				'label'       => __( 'Username or Email Address', 'ultimate-member' ),
				'id'          => 'user_login',
				'required'    => true,
				'value'       => '',
				'placeholder' => __( 'Enter Username or Email Address', 'ultimate-member' ),
				'validation'  => 'user_login',
			)
		),
		'hiddens'   => array(
			'um-action' => 'password-reset-request',
			'nonce'     => wp_create_nonce( 'um-lostpassword' ),
		),
		'buttons'   => array(
			'new-password' => array(
				'type'  => 'submit',
				'label' => __( 'Get New Password', 'ultimate-member' ),
			),
		),
	); */

	// you may change hiddens for this form
    $args['hiddens']['{hidden_name}'] = '{hidden value}';
    // you may add fields to this form
    $args['fields'][] = array(
        // {field data} see necessary arguments for the fields in ultimate-member/includes/frontend/class-form.php
        // 'id' and 'type' are required
    );
    return $args;
}
add_filter( 'um_lostpassword_form_args', 'mylostpassword_form_args', 10, 1 );