Here is a code to get the Quick stats report template with data:

include 'PapApi.class.php';

$session = new Pap_Api_Session("http://URL_to_PAP/scripts/server.php");
if(!$session->login("", "password")) {
  die("Cannot login. Message: ".$session->getMessage());
// more details on session creation here

$request = new Gpf_Rpc_DataRequest('Pap_Merchants_Reports_QuickReportData', 'load', $session);
//$request->setField('isInitRequest', 'Y'); // specifies that the filter you've set under the Quick report as default should be used, without this it displays "All" data
//$request->setField('filterType', 'quick_reports'); // used in conjuction with the above, without this line it won't set the default filter.
//$request->addFilter('userid', '=', '11111111'); // this is how you can specify custom filters, more info about filtering here

try {
catch(Exception $e) {
  die("API call error: ".$e->getMessage());

$data = $request->getData();

echo $data->getValue('htmlContent');

If instead of the template you want raw data you can use this approach.