app/bundles/PluginBundle/Resources/views/Auth/postauth.html.twig

{% set contentOnly = true %}
{% extends '@MauticCore/Default/content.html.twig' %}

{% block mauticContent 'social' %}
{% block headerTitle '' %}

{% block content %}
{% set data = data|json_encode %}
<script>
function postFormHandler() {
    var opener = window.opener;
    if (opener && typeof opener.postAuthCallback == 'function') {
        opener.postAuthCallback({$data});
    } else {
        Mautic.refreshIntegrationForm();
    }
    window.close()
}
{% if message is not empty and 'success' is same as alert %}
(function() { postFormHandler(); })();
{% endif %}
</script>

{% if message is not empty %}
    <div class="alert alert-{{ alert }}">
        {{ message|purify }}
    </div>
{% endif %}
<div class="row">
    <div class="col-sm-12 text-center">
        <a class="btn btn-lg btn-primary" href="javascript:void(0);" onclick="postFormHandler();">
            {{ 'mautic.integration.closewindow'|trans }}
        </a>
    </div>
</div>
{% endblock %}