Fatal error: Uncaught Error: Class "core_external\external_api" not found in C:\xamppasploms\htdocs\asaploms\payment\gateway\paypal\classes\external\transaction_complete.php:36 Stack trace: #0 {main} thrown in C:\xamppasploms\htdocs\asaploms\payment\gateway\paypal\classes\external\transaction_complete.php on line 36