Acho que é simples

Erro ao FINALIZAR a compra, alguem poderia me ajudar?

Fatal error: Uncaught exception 'Exception' with message 'PagSeguroLibrary: cURL library is required.' in C:\xampp\htdocs\custom_scripts\PagSeguroLibrary\utils\PagSeguroHttpConnection.class.php:33 Stack trace: #0 C:\xampp\htdocs\custom_scripts\PagSeguroLibrary\service\PagSeguroPaymentService.class.php(73): PagSeguroHttpConnection->__construct() #1 C:\xampp\htdocs\custom_scripts\PagSeguroLibrary\domain\PagSeguroPaymentRequest.class.php(627): PagSeguroPaymentService::createCheckoutRequest(Object(PagSeguroAccountCredentials), Object(PagSeguroPaymentRequest), false) #2 C:\xampp\htdocs\dntpagseguro.php(21): PagSeguroPaymentRequest->register(Object(PagSeguroAccountCredentials)) #3 {main} thrown in C:\xampp\htdocs\custom_scripts\PagSeguroLibrary\utils\PagSeguroHttpConnection.class.php on line 33