PHP Push Notifications

Question

I've been working on a custom web application for a while in which the user can add a reminder and then choose when to be notified. Basically when the current time matches the time chosen by the user, they should then get a push notification. I've set up a cron job, where the php file is run every minute, but the push notifications simply do not work.

    $curDate=   date('Y-m-d');
    date_default_timezone_set("Europe/Athens");
    $curTime=   date('H:i:s');
  
    $reminders = $pdo->prepare("SELECT * FROM con_reminders ORDER BY id desc");
    $reminders->execute();
    $reminders = $reminders->fetchAll();
 
foreach($reminders as $reminder){
  $event_id = $reminder['event_id'];
  $event_time = $reminder['event_time'];
  $event_time_1 = $reminder['event_time_1'];
  $event_time_2 = $reminder['event_time_2'];
  $event_time_3 = $reminder['event_time_3'];
  $event_date = $reminder['event_date'];
  $event_notes = $reminder['event_notes'];

        
    if  ( $curDate ==  $event_date &&  $curTime == $event_time ){
        ?>
        <script>
        
        function notifyMe() {
 
  if (!("Notification" in window)) {
    alert("The browser does not support desktop notifications!");
  }

  else if (Notification.permission === "granted") {
     let notification = new Notification("Hello!!");
  }
else if (Notification.permission !== "denied") {
    Notification.requestPermission().then(function (permission) {
         if (permission === "granted") {
        let notification = new Notification("Hello!!");
      }
    });
  }
  </script>
<?php } ?>

I don't know if the problem lies in this code or I'm completely missing something else entirely. Any help would be really appreciated.