Hello I'm trying to take innerHTML of the elements and put them into PDF. After generate PDF, the PDF file is blank.

What am I doing wrong?

add_action( 'template_redirect', 'pdf_to' );
function pdf_to(){
?> 
<script 
src="https://cdnjs.cloudflare.com/ajax/libs/html2pdf.js/0.10.1/html2pdf.bundle.min.js" 
integrity="sha512- 
GsLlZN/3F2ErC5ifS5QtgpiJtWd43JWSuIgh7mbzZ8zBps+dvLusV+eNQATqgA/HdeKFVgA5v3S/cIrLF7QnIg==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>
<script>
function to_pdf(){
    console.log("tutaj1");
    
    const btn = document.getElementById("pdf");

    btn.addEventListener("click", function(){
    var element = document.getElementById("test");
    console.log(element);
    html2pdf().from(element).save('filename.pdf');
    console.log("tutaj2");
    });
}
if (window.addEventListener) {
    window.addEventListener("load", to_pdf, false);
}
else if (window.attachEvent) {
    window.attachEvent("onload", to_pdf);
}
else {
    window.onload = to_pdf; 
}

</script>
<?php
}