How to make my update query work using my code below - php

Question

I am setting up an update profile page using php and a bit of laravel. I have an if check that checks if the form is submitted and I have an update query.
The update query only works outside of the if statement and I have no idea why. If I put in inside of the if statement it doesnt do anything. I have checked if all the names are the same as in my sql database and they are all correct.
<form class="form" id="registrationForm">
<div class="form-group">
<div class="col-xs-6">
<label for="first_name">
<h4>Voornaam</h4></label>
<input type="text" class="form-control" name="voornaam" id="first_name" placeholder="<?= $user->voornaam; ?>" title="enter your first name if any.">
</div>
</div>
<div class="form-group">
<div class="col-xs-6">
<label for="last_name">
<h4>Achternaam</h4></label>
<input type="text" class="form-control" name="achternaam" id="last_name" placeholder="<?= $user->achternaam; ?>" title="enter your last name if any.">
</div>
</div>
<div class="form-group">
<div class="col-xs-6">
<label for="phone">
<h4>Gebruikersnaam</h4></label>
<input type="text" class="form-control" name="gebruikersnaam" id="username" placeholder="<?= $user->gebruikersnaam; ?>" title="enter your phone number if any.">
</div>
</div>
<div class="form-group">
<div class="col-xs-6">
<label for="mobile">
<h4>Telefoon nummer</h4></label>
<input type="text" class="form-control" name="telefoonnummer" id="mobile" placeholder="<?= $user->telefoonnummer; ?>" title="enter your mobile number if any.">
</div>
</div>
<div class="form-group">
<div class="col-xs-12">
<label for="email">
<h4>Email</h4></label>
<input type="email" class="form-control" name="email" id="email" placeholder="<?= $user->email; ?>" title="enter your email.">
</div>
</div>
<div class="form-group">
<div class="col-xs-12">
<br>
<button class="btn btn-lg btn-success" type="submit" name="submit"><i class="glyphicon glyphicon-ok-sign"></i> Sla op</button>
<button class="btn btn-lg" type="reset" name="resetww"><i class="glyphicon glyphicon-repeat"></i> Verander wachtwoord</button>
</div>
</div>
</form>
<?php
if (isset($_POST['submit'])) {
$voornaam = $_POST['voornaam'];
$achternaam = $_POST['achternaam'];
$gebruikersnaam = $_POST['gebruikersnaam'];
$telefoonnummer = $_POST['telefoonnummer'];
$email = $_POST['email'];
App\User::where('klant_id', 1)->update(['gebruikersnaam' => $gebruikersnaam, 'voornaam' => $voornaam, 'achternaam' => $achternaam, 'email' => $email ,'telefoonnummer' => $telefoonnummer]);
}
?>
I want my database to be updated

Answer 1

Put the tag in your form, the PHP is trying to find de POST but you are not sending it.
method="POST"

Answer 2

First of all mention form method as below and use csrf token
#csrf
Why u can't use controller to complete this work
First of all use controller, Then make a method to update information
public function update_user(Request $request){
if ($request->isMethod('post')) {
$data = $request->all();
User = new User();
$voornaam = $_POST['voornaam'];
$achternaam = $data['achternaam'];
$gebruikersnaam = $data['gebruikersnaam'];
$telefoonnummer = $data['telefoonnummer'];
$email = $data['email'];enter code here
}
}