WordPressの管理画面にIntercomのウィジェットを出す時のスニペット ref: https://qiita.com/motchi0214/items/451af013fde2034f436e

file0.php

<?php
/*
Plugin Name: Admin Intercom Widget
Plugin URI: https://gist.github.com/hideokamoto/c0b9002ad73f145e1c6d6bc3b99f2b7b
Description: 管理画面にIntercomのWidget出すプラグイン
Author: hideokamoto
Version: 0.0.1
*/
final class My_IntercomWidget {
    /**
     * Show intercom widget in the WordPress Dashboard
     */
    public function show_intercom_widget () {
        ?>
        <script>
        const APP_ID = "YOUR_APP_ID";

        window.intercomSettings = {
                app_id: APP_ID
            };
        (function(){var w=window;var ic=w.Intercom;if(typeof ic==="function"){ic('reattach_activator');ic('update',intercomSettings);}else{var d=document;var i=function(){i.c(arguments)};i.q=[];i.c=function(args){i.q.push(args)};w.Intercom=i;function l(){var s=d.createElement('script');s.type='text/javascript';s.async=true;s.src='https://widget.intercom.io/widget/' + APP_ID;var x=d.getElementsByTagName('script')[0];x.parentNode.insertBefore(s,x);}if(w.attachEvent){w.attachEvent('onload',l);}else{w.addEventListener('load',l,false);}}})()
        </script>
        <?php
    }
}

add_action('admin_footer', array('My_IntercomWidget', 'show_intercom_widget'));