How to track errors on the site?

Question

opencart

Online store customers sometimes complain that they can't place an order. Something hung, then when choosing a payment on the site, the form simply closed, confirming the order, but not opening the payment window. Apparently there are some technical errors (somewhere the scripts were not loaded, somewhere there is incompatibility with old browsers, something else), which I cannot reproduce. How do you catch them?
For example, the Yandex webvisor suggests itself, I’ll probably start with it, maybe it will be seen what the problem is on the side of a particular client. Are there any other solutions?

Answer 1

Everything is in your error log

Answer 2

Google search console

Answer 3

public function confirmUser($event_id){
    $event = CreateEvent::find($event_id); // тут get не нужен
    $part = DB::table('participants')->where('event',$event->event_id)->get(); // тут get нужен

    $followers = collect([]);
    foreach($part as $participant) {
      $followers->push(['user_id' => $participant->follower]);
    }
    return $followers;
}