Need to hook into plugin

Iv got most of the php writen but when and right now it is pulling in just an empty div

any idea why?

php code output
<div class=”g-recaptcha” data-sitekey=”MYKEY” data-theme=”light”></div>

——————

<?php

class Ncr_Custom_Login_Captcha extends Ncr_No_Captcha_Recaptcha {

	public static function initialize() {

		// initialize if login is activated
		if ( isset(self::$plugin_options['captcha_login']) && self::$plugin_options['captcha_login'] == 'yes') {
			// add captcha header script to WordPress header
			add_action( 'wp_head', array( __CLASS__, 'header_script' ) );

			// adds the captcha to the custom login form
			add_action( 'custom_captcha_login', array( __CLASS__, 'display_captcha' ) );

			// authenticate the captcha answer
			add_action( 'wp_authenticate_user', array( __CLASS__, 'validate_captcha_custom_login' ), 10, 2 );
		}
	}

	/**
	 * Verify the captcha answer
	 *
	 * @param $user string login username
	 * @param $password string login password
	 *
	 * @return WP_Error|WP_user
	 */

	public static function validate_captcha_custom_login( $user, $password ) {
		if ( ! isset( $_POST['g-recaptcha-response'] ) || ! self::captcha_verification() ) {
			// Pop error message into $error_msg
		}

		return $user;
	}
}

——————-
require_once dirname(__FILE__). '/custom-login.php';
Ncr_Custom_Login_Captcha::initialize();
—————————–
On the form in question I have added a fire action
{do_action( 'custom_captcha_login' )}

I think i just found the answer…

`/** reCAPTCHA header script */
public static function header_script() {

$lang_option = self::$language;

// if language is empty (auto detected chosen) do nothing otherwise add the lang query to the
// reCAPTCHA script url
if ( isset( $lang_option ) && ( ! empty( $lang_option ) ) ) {
$lang = “?hl=$lang_option”;
} else {
$lang = null;
}

echo ‘<script src=”https://www.google.com/recaptcha/api.js&#8217; . $lang . ‘” async defer></script>’ . “\r\n”;
}

/**
* Enqueue the Google ReCAPTCHA script using the WP system.
*
* @since 1.0.3
*/
public static function enqueue_header_script() {

// if language is empty (auto detected chosen) do nothing otherwise add the lang query to the
// reCAPTCHA script url
if ( ! empty( self::$language ) ) {
$lang = “?hl={self::$language}”;
} else {
$lang = ”;
}

$src = ‘https://www.google.com/recaptcha/api.js&#8217; . $lang;

wp_enqueue_script( self::$script_handle, $src, false, false, true );
}`

Its not getting called into the custom login page

Now it seems when validation fails I get a 500 server error
PHP Fatal error: Class name must be a valid object or a string

Update to custom-login.php

Good news, the login is working only problem is getting the error message to display. So far no error message is showing.

<?php

class Ncr_Custom_Login_Captcha extends Ncr_No_Captcha_Recaptcha {

	public static function initialize() {

		// initialize if login is activated
		if ( isset(self::$plugin_options['captcha_login']) && self::$plugin_options['captcha_login'] == 'yes') {
			// add captcha header script to WordPress header
			add_action( 'wp_head', array( __CLASS__, 'header_script' ) );

			// adds the captcha to the custom login form
			add_action( 'custom_captcha_login', array( __CLASS__, 'display_captcha' ) );

			// authenticate the captcha answer
			add_action( 'wp_authenticate_user', array( __CLASS__, 'validate_captcha_custom_login' ), 10, 2 );
		}
	}

	/**
	 * Verify the captcha answer
	 *
	 * @param $user string login username
	 * @param $password string login password
	 *
	 * @return WP_Error|WP_user
	 */

	public static function validate_captcha_custom_login( $user, $password ) {
		if ( ! isset( $_POST['g-recaptcha-response'] ) || ! self::captcha_verification() ) {
			// Pop error message into $error_msg
			echo $error_message;
		}

		return $user;
	}
}

Latest code iteration

<?php

class Ncr_Custom_Login_Captcha extends Ncr_No_Captcha_Recaptcha {

	public static function initialize() {

		// initialize if login is activated
		if ( isset(self::$plugin_options['captcha_login']) && self::$plugin_options['captcha_login'] == 'yes') {
			// add captcha header script to WordPress header
			add_action( 'wp_head', array( __CLASS__, 'header_script' ) );

			// adds the captcha to the custom login form
			add_action( 'custom_captcha_login', array( __CLASS__, 'display_captcha' ) );

			// authenticate the captcha answer
			add_action( 'wp_authenticate_user', array( __CLASS__, 'validate_captcha_custom_login' ), 10, 2 );
		}
	}

	/**
	 * Verify the captcha answer
	 *
	 * @param $user string login username
	 * @param $password string login password
	 *
	 * @return WP_Error|WP_user
	 */

	public static function validate_captcha_custom_login( $user, $password ) {
		if ( ! isset( $_POST['g-recaptcha-response'] ) || ! self::captcha_verification() ) {

		// Stop user and populate error message $error_message into $error_msg
		}

		// Do nothing and let user login
	}
}