Ultimate Member v3: Password Reset. Lost Password form validation using Email Address only

functions.php

function um_021522_form_notice( $text, $key ) {
     if ( 'lostpassword-info' === $key ) {
         $text = __( 'Please enter your email address. You will receive an email message with instructions on how to reset your password.', 'ultimate-member' );
     }
 
     return $text;
}
add_filter( 'um_form_notice', 'um_021522_form_notice', 10, 2 );

function um_021522_lostpassword_form_args( $lostpassword_args ) {
	foreach ( $lostpassword_args['fields'] as &$field_data ) {
		if ( 'user_login' === $field_data['id'] ) {
			$field_data['label']       = __( 'Email Address', 'ultimate-member' );
			$field_data['placeholder'] = __( 'Enter Email Address', 'ultimate-member' );
		}
	}
	return $lostpassword_args;
}
add_filter( 'um_lostpassword_form_args', 'um_021522_lostpassword_form_args', 10, 1 );

function um_021522_reset_password_error( $lostpassword_form ) {
	if ( ! empty( $_POST['user_login'] ) ) {
		$user_login = sanitize_text_field( wp_unslash( $_POST['user_login'] ) );
		if ( ! is_email( $user_login ) ) {
			$lostpassword_form->add_error( 'user_login', __( 'Please provide your email address.', 'ultimate-member' ) );
		}
	}
}
add_action( 'um_lostpassword_errors_hook', 'um_021522_reset_password_error', 10, 1 );