'your access token', 'refresh_token' => 'your refresh token'); $wrap = new CS_REST_Campaigns('Campaign ID to Test', $auth); $result = $wrap->send_preview(array( 'test1@test.com', 'test2@test.com' ), 'Fallback'); echo "Result of POST /api/v3.1/campaigns/{id}/sendpreview\n
"; if($result->was_successful()) { echo "Preview sent with code\n
".$result->http_status_code; } else { echo 'Failed with code '.$result->http_status_code."\n
";
    var_dump($result->response);
    echo '
'; }