Fatal error: Uncaught Facebook\Exceptions\FacebookSDKException: Required "app_id" key not supplied in config and could not find fallback environment variable "FACEBOOK_APP_ID" in D:\xampp-iton\htdocs\vicro-cn\wp-content\plugins\nextend-facebook-connect\Facebook\Facebook.php:139 Stack trace: #0 D:\xampp-iton\htdocs\vicro-cn\wp-content\plugins\nextend-facebook-connect\nextend-facebook-connect.php(160): Facebook\Facebook->__construct(Array) #1 D:\xampp-iton\htdocs\vicro-cn\wp-content\plugins\nextend-facebook-connect\nextend-facebook-connect.php(123): new_fb_login_action() #2 D:\xampp-iton\htdocs\vicro-cn\wp-includes\class-wp-hook.php(286): new_fb_login('') #3 D:\xampp-iton\htdocs\vicro-cn\wp-includes\class-wp-hook.php(310): WP_Hook->apply_filters(NULL, Array) #4 D:\xampp-iton\htdocs\vicro-cn\wp-includes\plugin.php(453): WP_Hook->do_action(Array) #5 D:\xampp-iton\htdocs\vicro-cn\wp-login.php(446): do_action('login_init') #6 {main} thrown in D:\xampp-iton\htdocs\vicro-cn\wp-content\plugins\nextend-facebook-connect\Facebook\Facebook.php on line 139