Accept Terms of Service in Ultimate Facebook Connect

So my issue is the same one that is found here: https://premium.wpmudev.org/forums/topic/ultimate-facebook-5

Basically I have terms of service on my website and I want the user to be forced to accept the TOS when registering with Ultimate Facebook. Right now Ultimate Facebook bypasses the TOS.

Where exactly should the below code be added?

function my_fb_add_tos_box ($fields) {
$fields[] = array(
"name" => "tos",
"description" => "I agree to Terms of Services",
"type" => "checkbox",
);
return $fields;
}
add_filter('wdfb-registration_fields_array', 'my_fb_add_tos_box');

function my_fb_require_tos_box ($user_id, $he, $registration, $model) {
if ($registration['tos']) return true;

$model->delete_wp_user($user_id);
wp_redirect(site_url("/my-tos-page"));
die;
}
add_action("wdfb-user_registered-postprocess", "my_fb_require_tos_box", 10, 4);