We don't support the integrationservic.es PHP, but if you use our PHP wrapper located here, you can use the following code to generate an export contacts activity.
$ConstantContact = new ConstantContact("oauth2", $apiKey, $username, $accessToken);
//Update your username and list ID in the string below
$exportString = "activityType=EXPORT_CONTACTS&fileType=CSV&exportOptDate=true&exportOptSource=true&exportListName=true&sortBy=DATE_DESC&columns=FIRST%20NAME&columns=LAST%20NAME&listId=http%3A%2F%2Fapi.constantcontact.com%2Fws%2Fcustomers%2Fusername%2Flists%2F1";
$export = $ConstantContact->bulkAddContacts($exportString);
This generates an activity in the account to export the contacts, which usually takes a few minutes. The response from our server when you create the activity will return a link to download the file that is created.
API Support Specialist
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