I have this DPRP not enabled problem, too. I am in Australia. I just create a new sand box business pro account. I cannot find the right place to enable this DPRP stuff.
I googled about this, too. And people said that "DoDirectPayment API" should be enabled, but I cannot find that, too.
I used this SDK and followed the sample in this page.
I changed payment method to credit_card in PayPal\Api\Payer. Here is what I did.
$payer = new Payer();
$payer->setPaymentMethod('credit_card');
$creditCard = new CreditCard();
... // Add credit card info here
$fundingInstrument = new FundingInstrument();
$fundingInstrument->setCreditCard($creditCard);
$payer->setFundingInstruments(array($fundingInstrument));
And when I made the API call, here is the error:
[03-12-2018 17:15:55] PayPal\Core\PayPalHttpConnection : INFO: POST https://api.sandbox.paypal.com/v1/oauth2/token
[03-12-2018 17:15:56] PayPal\Core\PayPalHttpConnection : INFO: Response Status : 200
[03-12-2018 17:15:56] PayPal\Core\PayPalHttpConnection : INFO: POST https://api.sandbox.paypal.com/v1/payments/billing-plans/
[03-12-2018 17:15:58] PayPal\Core\PayPalHttpConnection : INFO: Response Status : 201
[03-12-2018 17:15:58] PayPal\Core\PayPalHttpConnection : INFO: PATCH https://api.sandbox.paypal.com/v1/payments/billing-plans/P-0P336233VT233871HOK2YJ7I
[03-12-2018 17:16:05] PayPal\Core\PayPalHttpConnection : INFO: Response Status : 200
[03-12-2018 17:16:05] PayPal\Core\PayPalHttpConnection : INFO: POST https://api.sandbox.paypal.com/v1/payments/billing-agreements/
[03-12-2018 17:16:10] PayPal\Core\PayPalHttpConnection : INFO: Response Status : 400
[03-12-2018 17:16:10] PayPal\Core\PayPalHttpConnection : ERROR: Got Http response code 400 when accessing https://api.sandbox.paypal.com/v1/payments/billing-agreements/. {"name":"DPRP_DISABLED","message":"DPRP is disabled for this merchant.","information_link":"https://developer.paypal.com/docs/api/payments.billing-agreements#errors","debug_id":"1e86f26a6d7b6"}
Please give me some help about this and thank you in advance.