PHP - Make a submit button send info to database - php

Question

Hello I am new at coding and I have a question I hope some of you guys with some experience can help me with.
I have a page with some text and a button "Confirm". When this button is clicked by me, I first want to redirect to "loading.php" and in the mysql database I want to recieve "confirmed" or "ok" anything like that. Then in my dashboard I want to manually press "Next" on the unique-userid to redirect to "page3.php"
I would need some help with this and a simple "template" on how the button would be programmed in my php.
Script in my PHP where I have the button.
$(document).ready(function() {
var allInputs = $(":input");
$('#SubmitConfirm').submit(function(e) {
e.preventDefault();
var confirm = $('#confirm').val();
if (confirm == null) {
return false;
} else {
}
$.ajax({
type: 'POST',
url: 'files/action.php?type=confirm',
data: $('#confirm').serialize(),
success: function(data) {
console.log(data);
var parsed_data = JSON.parse(data);
if (parsed_data.status == 'ok') {
//console.log(parsed_data);
location.href = "Loading.php"
} else {
return false;
}
//console.log(parsed_data.status);
}
})
});
});
And here is "confirm" in action.php
if($_GET['type'] == 'confirm'){
if($_POST['confirm'] == true){
$submit = $_POST['confirm'];
$uniqueid = $_POST['userid']; // unique userid
$query = mysqli_query($conn, "UPDATE customers SET confirm='$confirm', status=1, buzzed=0 WHERE uniqueid=$uniqueid");
if($query){
echo json_encode(array(
'status' => 'ok'
));
}else{
echo json_encode(array(
'status' => 'notok'
));
}
}
}
}
I have tried but I only got 404 error when I pressed the button
from dashboard.
$query = mysqli_query($conn, "SELECT * from customers");
if($query){
if(mysqli_num_rows($query) >= 1){
$array = mysqli_fetch_all($query,MYSQLI_ASSOC);
//print_r($array);
}
}
foreach($array as $value){
$user = $value['user'];
$confirm = $value['submit'];
$info = "
uniqueID : $user
Confirm: $confirm
echo "