Multi Business unit creates a duplicate lead in salesforce

The problem was simply that when the call was made I did not have access, using the Pardot API I realized to make an API call I will need to first get an API key (by sending email, password, and user_key), then every API call will require the api_key and the user_key along with any parameters need for the request you're making.

In short here is the code from my approach.

In my Pardot.cls (which is used by my trigger and trigger handler class) I have methods like createProspectsByLead() which fires APIRequest() that first gets the API Key, and then uses that key and the user_key to make another HttpRequest.

The full code implementation can be found here

All API Request use this method

@future (callout=true)
private static void APIRequest(String url, String body){
    HttpResponse response = httpCallout( url, 'user_key='+getConnectorUserKey()+'&api_key='+getAPIKey()+'&'+ body );
}

Get API Key

public static String getAPIKey(){
    HttpResponse response = httpCallout(
        'https://pi.pardot.com/api/login/version/3?', //URL
        'email='+getConnectorEmail()+'&password='+getConnectorPassword()+'&user_key='+ getConnectorUserKey() //Body
    );

    /* Parse API Response */
    Dom.Document doc = new Dom.Document();
    doc.load(response.getBody());
    Dom.XMLNode root = doc.getRootElement();
    if(root.getName()=='rsp') {
        for(Dom.XMLNode node1: root.getChildElements()) {
            if(node1.getName()=='err') {
                String err = root.getChildElement('err', null).getText();
                String code = root.getChildElement('err', null).getAttribute('code', null);
                System.debug('::API REQUEST ERROR:: '+code+' - '+err);
                return err;
            }
            if(node1.getName()=='api_key') {
                /* Store API in variable */
                // TODO: Store API for 1 hour in Global__c
                String api_key = root.getChildElement('api_key', null).getText();
                return api_key;
            }
        }
    }

    /* This should never happen */
    return '';
}

Each callout uses the httpCallout method

public static HttpResponse httpCallout(String url, String body){
    HttpRequest     request     = new HttpRequest();
    HttpResponse    response    = new HttpResponse();
    Http            http        = new Http();

    request.setEndPoint(url);
    request.setBody(body);
    request.setMethod('POST');

    /* Try to send the request */
    try {
        response = http.send(request);
        System.debug('::RESPONSE::'+response.getBody());
        return response;
    } catch(System.CalloutException e) {
        System.debug('ERROR: '+ e);
        return null;
    }
}

Be sure to see my github repo of this complete implementation and even contribute to it as a community resource.