At the moment I’m going through the onboarding process, call this API call, where i can get the action URL so that the onboarding starts. So I request this API Call:

https://api-m.sandbox.paypal.com/v2/customer/partner-referrals

with this payload:

{
    "tracking_id": "868gkjhkhjlklj",
    "operations": [{
    "operation": "API_INTEGRATION",
    "api_integration_preference": {
          "rest_api_integration": {
                "integration_method": "PAYPAL",
                "integration_type": "THIRD_PARTY",
                "third_party_details": {
                "features": [
                    "PAYMENT",
                    "REFUND"
                 ]
          }
      }
  }
 }],
   "products": [
    "EXPRESS_CHECKOUT"
 ],
 "legal_consents": [{
    "type": "SHARE_DATA_CONSENT",
    "granted": true
}]
}

I get a response of this JSON:

{
    "links": [
        {
           "href": "https://api.sandbox.paypal.com/v2/customer/partner-referrals/M2FkMjQ2MjMtMmRkZC00MjYxLWE2NWQtMmVmMjJlZjU1OTE2MTk4SkhnOFViTHhORHh3cUM3Q1BqRWc2dHJzYXJMcGxLMzRKN1ZpR0Jldz12Mg==",
            "rel": "self",
            "method": "GET",
            "description": "Read Referral Data shared by the Caller."
          },
        {
            "href": "https://www.sandbox.paypal.com/bizsignup/partner/entry?referralToken=M2FkMjQ2MjMtMmRkZC00MjYxLWE2NWQtMmVmMjJlZjU1OTE2MTk4SkhnOFViTHhORHh3cUM3Q1BqRWc2dHJzYXJMcGxLMzRKN1ZpR0Jldz12Mg==",
            "rel": "action_url",
            "method": "GET",
            "description": "Target WEB REDIRECT URL for the next action. Customer should be redirected to this URL in the browser."
        }
    ]
}

And i add this action_url to the JavaScript or link button on the page:

        <div dir="ltr" style="text-align: left;" trbidi="on">
        <script>
            (function (d, s, id) {
                var js, ref = d.getElementsByTagName(s)[0];
                if (!d.getElementById(id)) {
                    js = d.createElement(s);
                    js.id = id;
                    js.async = true;
                    js.src = "https://www.paypal.com/webapps/merchantboarding/js/lib/lightbox/partner.js";
                    ref.parentNode.insertBefore(js, ref);
                }
            }(document, "script", "paypal-js"));
        </script>
        <a data-paypal-button="true" href="<action_url>&displayMode=minibrowser" target="PPFrame">Sign up for PayPal</a>
    </div>

This is the link on my screen where I go through the onboarding:

Then I’m in the onboarding process.

I don’t understand what to do next, there is no documentation that I can find to get the merchant_id and store this against my user in the database so that I can use this merchant_id and allow the merchant / seller to be paid for there goods. What do I do next?

I’m using Paypal Rest API V2, should I use V1? or continue to use V2 as its a new implementation?