platform_fees is not apply when use DIGITAL_GOODS as a category

[dipeshc]

$data = [
    "intent" => "CAPTURE",
    "purchase_units" => [
        [
            "amount" => [
                "currency_code" => "USD",
                "value" => "100",
                "breakdown" => [
                    "item_total" => [
                        "currency_code" => "USD",
                        "value" => "100",
                    ]
                ]
            ],
            "description" => "Some goods description",
            'items' => [
                [
                    'name' => "certificate-_pdf",
                    'unit_amount' => [
                        "currency_code" => "USD",
                        "value" => "100"
                    ],
                    'quantity' => 1,
                    'description' => "quiz completion certificate pdf",
                    'category' => 'DIGITAL_GOODS',
                ]
            ],
            "payee" => [
                "email_address" => "merchant_email_address"
            ],
            "payment_instruction" => [
                "disbursement_mode" => "INSTANT",
                "platform_fees" => [
                    [
                        "amount" => [
                            "currency_code" => "USD",
                            "value" => "10.00"
                        ],
                    ],
                ],
            ],
        ]
    ]
];

above is the order create request for rest API.

seller on my site provides the digital goods and when customers buy it, the seller should get payment directly to their account and I should get a commission in my account.

problem is that, for digital goods, there is no shipping detail required but it'll show shipping detail during payment checkout. 

Another issue is that, platform_fees (partner commission) is not applied when I added category = DIGITAL_GOODS

In my case, there is no physical goods involved. PayPal says that digital_goods is not available for commerce platform.

How can I achieve this?

Thank you.