phpmailer体内的JavaScript

In phpmailer, I want to use a script tag inside the variable body to do something in the click event. For example, this is the body which I send in the email. I put it in $mail->body='<html>..<script>....'

<html>
 <head>
        <title></title>
            <script>
                document.getElementById("btn").onclick=function(){clt()};
                function clt(){
                    console.log("okk");
                }
                console.log("okk");
            </script>
        </head>
        <script>
                document.getElementById("btn").onclick=function() {clt()};
                function clt(){
                    console.log("okk");
                }
                console.log("okk");
            </script>
        <body>
            <p id="txt">tetet</p><button  id="btn" onclick="clt()">click me! </button>
            <script>
                document.getElementById("btn").onclick=function() {clt()};
                function clt(){
                    console.log("okk");
                }
                console.log("okk");
            </script>
        </body>
        </html>

This isn't anything to do with PHPMailer; email clients do not run javascript, so you simply can't do this.