code snippet not working on my page

Hi PHP snippet team,

I am trying to use a code snippet with auto forward url script but its not working while adding the snippet short code on a page. After 45 seconds the page shall be auto-forward to a specific URL.

Screenshots:
Page with shortcode: https://www.screencast.com/t/13YqWfvM9CA
PHP Snippent: https://www.screencast.com/t/itkPL0IvO57U and https://www.screencast.com/t/MRoZD7mOV5
Code:

<p><!-- Modify this according to your requirement – core script and suffix grabbing --></p>
<h3 style="text-align: center;"><span style="color: #ffffff; background-color: #039e00;">►Auto-redirecting after <span id="countdown">45</span> seconds◄</span></h3>
<p><!-- JavaScript part --><br /><script type="text/javascript">

function findGetParameter(parameterName) {
    var result = null,
        tmp = [];
    location.search
        .substr(1)
        .split("&")
        .forEach(function (item) {
          tmp = item.split("=");
          if (tmp[0] === parameterName) result = decodeURIComponent(tmp[1]);
        });
    return result;
}

    
    // Total seconds to wait
    var seconds = 45;
    
    function countdown() {
        seconds = seconds - 1;
        if (seconds < 0) {
            // Chnage your redirection link here
var tid = findGetParameter('tid');
window.location = "https://google.com" + '?tid='+tid;
        } else {
            // Update remaining seconds
            document.getElementById("countdown").innerHTML = seconds;
            // Count down using javascript
            window.setTimeout("countdown()", 1000);
        }
    }
    
    // Run countdown function
    countdown();
    
</script></p>

I am looking forward on your advice.

Best, Alex

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