Stripe PaymentIntent with confirmation method manual fails every time

Question

I'm using Laravel with a personal integration of the Stripe API (using Stripe API from github).
Everything was working fine until i switched to manual confirmation mode, and now i'm receiving the following error:

This PaymentIntent pi_**************uVme cannot be confirmed using your publishable key because its `confirmation_method` is set to `manual`. Please use your secret key instead, or create a PaymentIntent with `confirmation_method` set to `automatic`.

Any idea?
This is my current code (which is not working):

Stripe::setApiKey(config('services.stripe.secret')); // config('services.stripe.secret') returns "sk_test_gFi********************nMepv"

$paymentIntent = PaymentIntent::create([
    'amount' => $orderSession->order_total * 100,
    'currency' => 'eur',
    'description' => "Pagamento di ".(price($orderSession->order_total))."€ a ".$orderSession->user->user_name." in data ".(now()->format("d-m-Y H:m:s")),
    'metadata' => [
        'subtotal' => $orderSession->order_subtotal,
        'user'=> "{$orderSession->user_id} : {$orderSession->user->user_email}",
        'wines'=> substr(
                        $orderSession->wines()->select('wine_id', 'quantity')->get()->each(
                            function($el){
                                $el->q= $el->quantity;
                                $el->id = $el->wine_id;
                                unset($el->wine_id, $el->pivot, $el->quantity);
                            }
                        )->toJson(),
                        0,
                        500
                    ),
    ],
    'confirmation_method' => 'manual',
]);

JS frontend:

<button class="myButtonPayment" id="card-button" type="button" data-secret="{!!$stripePaymentIntent->client_secret!!}" ><span>Pay</span></button>
...
<script>
cardButton.addEventListener('click', function() {
    if(!document.getElementById('order_telephone_number').value || /^\+?[0-9 ]{6,20}$/.test(document.getElementById('order_telephone_number').value)){
           stripe.handleCardPayment(
               clientSecret, cardElement, {
                   payment_method_data: {
                         billing_details: {name: cardholderName.value}
                   }
               }
           ).then(function (result) {
               if (result.error) {
                   console.log(result.error);
              } else {
                   document.getElementById('myForm').submit();
              }
           });
    } 
});
</script>

The error is occuring when I click on the button (so is not related to the part of the code where I confirm the payment)

The error serialization is the following:

{
   "type":"invalid_request_error",
   "code":"payment_intent_invalid_parameter",
   "doc_url":"https://stripe.com/docs/error-codes/payment-intent-invalid-parameter",
   "message":"This PaymentIntent pi_1H3TQ*********T00uVme cannot be confirmed using your publishable key because its `confirmation_method` is set to `manual`. Please use your secret key instead, or create a PaymentIntent with `confirmation_method` set to `automatic`.",
   "payment_intent":{
      "id":"pi_1H3***********uVme",
      "object":"payment_intent",
      "amount":2060,
      "canceled_at":null,
      "cancellation_reason":null,
      "capture_method":"automatic",
      "client_secret":"pi_1H3TQ********T00uVme_secret_2T7Di*********nkoaceKx",
      "confirmation_method":"manual",
      "created":1594415166,
      "currency":"eur",
      "description":"....",
      "last_payment_error":null,
      "livemode":false,
      "next_action":null,
      "payment_method":null,
      "payment_method_types":[
         "card"
      ],
      "receipt_email":null,
      "setup_future_usage":null,
      "shipping":null,
      "source":null,
      "status":"requires_payment_method"
   }
}

Answer 1

Manual confirmation for Payment Intents is for server-side confirmation only (i.e. with your secret API key, not your publishable key). Setting confirmation_method to manual on a Payment Intent is the same as saying, "this Payment Intent can only be confirmed server-side".

You can read more about this in in the finalize payments on the server guide in Stripe's documentation.