I don't know much about this, but it seems to me that this functionality was removed from the paypal express module in ZC 1.3.8.
When I use the developers tool kit in ZC 1.3.7 and ZC 1.3.8 to look for 'authcapt', I get this for ZC 1.3.7 in the file includes/modules/payment/paypal/paypalwpp_admin_notification.php
Code:
Line #383 : if (method_exists($this, '_doVoid') && (MODULE_PAYMENT_PAYPALWPP_TRANSACTION_MODE == 'Auth Only' || (isset($_GET['authcapt']) && $_GET['authcapt']=='on'))) $output .= $outputVoid;
Line #384 : if (method_exists($this, '_doCapt') && (MODULE_PAYMENT_PAYPALWPP_TRANSACTION_MODE == 'Auth Only' || (isset($_GET['authcapt']) && $_GET['authcapt']=='on'))) $output .= $outputCapt;
Line #388 : if ($response['TRANSACTION_TYPE'] == 'Authorization' || (isset($_GET['authcapt']) && $_GET['authcapt']=='on')) {
On ZC 1.3.8, I see this:
Code:
Line #385 : if (method_exists($this, '_doVoid') && (MODULE_PAYMENT_PAYPALDP_TRANSACTION_MODE == 'Auth Only' || MODULE_PAYMENT_PAYFLOW_TRANSACTION_MODE == 'Auth Only' || (isset($_GET['authcapt']) && $_GET['authcapt']=='on'))) $output .= $outputVoid;
Line #386 : if (method_exists($this, '_doCapt') && (MODULE_PAYMENT_PAYPALDP_TRANSACTION_MODE == 'Auth Only' || MODULE_PAYMENT_PAYFLOW_TRANSACTION_MODE == 'Auth Only' || (isset($_GET['authcapt']) && $_GET['authcapt']=='on'))) $output .= $outputCapt;
Line #390 : if ($response['TRANSACTION_TYPE'] == 'Authorization' || ($response['TRANSACTIONTYPE'] == 'cart' && $response['PAYMENTTYPE'] == 'instant' && $response['PENDINGREASON'] == 'authorization') || (isset($_GET['authcapt']) && $_GET['authcapt']=='on')) {
Please someone confirm this, I don't want to keep using ZC 1.3.8 if this is not supported.