AUTHORIZED Orders with platform_fee 2024

[wekawekael]

 I need to setup paypal orders for an upcoming marketplace website (buyers, merchants and me the platform), but i fail to implement the platform_fee.

The workflow is simple:

1. Buyer buys Article - I create order with intent AUTHORIZE and authorize the order.

2. Buyer confirms received article and is happy with it - capture the order and send money to merchant (deduct a platform_fee).

Everything works fine besides the platform_fee. Its not even deducted from the amount I send.

I set the platform_fees when i capture the order (using srmklive for php laravel framework)

$captureResponse = $provider->captureAuthorizedPayment(
    $authorizationId,
    'INVOICE-' . uniqid(),
    $articlePrice,
    'Payment for article',
    [
        'platform_fees' => [
            [
                'amount' => [
                    'currency_code' => 'CHF',
                    'value' => 15 
                ],
                'payee' => [
                    'email_address' => $platformPayPalEmail
                ]
            ]
        ]
    ]
);

How to get this working?

1. Do I need an account upgrade? (Paypal partner)
2. Where do I activate this function in my sandbox developer account?

Im very confused about this process as I have read a lot of different informations about this topic.