怎么能让别的网站页面弹出客服插件页面联系客服？

把下面的代码放到你要添加客服的网页中，在需要点击弹出客服的按钮上加属性onclick="openchat()"

<button onclick="openchat()">联系客服</button>
<style>
    #chatbox{
        display: none;
        position: fixed;
        width:500px;
        height: 500px;
        bottom:50px;
        right:50px;
        box-shadow: 0 0 5px 0 rgb(0,0,0,40%);
    }
    #chatbox iframe{
        width: 100%;
        height: 100%;
    }
    #chatbox .close{
        position: absolute;
        right: 0;
        top: -30px;
        font-size: 14px;
        background-color: red;
        color:#fff;
        padding:2px 4px;
        cursor: pointer;
    }
</style>
<script>
    function openchat(){
        chatbox.style.display='block';
        if (chatlink.src == location.href){
            chatlink.src='https://www.baidu.com/'//替换为客服页面链接
        }
    }
    function hidechat(){
        chatbox.style.display='none'
    }
</script>
<div id="chatbox">
    <div class="close" onclick="hidechat()">关闭</div>
    <iframe src="" frameborder="0" id="chatlink"></iframe>
</div>