How to record a video to a web file using php

javascrit

function saveVideo(b) {
        var f = new FormData();
        f.append('videofile', b);
        var xhr=new XMLHttpRequest();
        xhr.open('POST','save.php');
        xhr.send(f);
      }

php

<?php
    if($_FILES['videofile']){
        $my_file = $_FILES['videofile'];
        $my_blob = file_get_contents($my_file['tmp_name']);
        file_put_contents(mktime() . '.webm', $my_blob);
    }
?>

I record a video in video/webm format via MediaRecorder and pass the blob to the saveVideo function, which in turn makes a POST request to the file save.php , but he responds with the code 500

source https://stackoverflow.com/questions/76502031/how-to-record-a-video-to-a-web-file-using-php