Code

    $url = 'https://post.transactionexpress.com/PostMerchantService.svc/CreditCardSale';


$ccNum = "371449635392376";
$expDate = "2012";
$amount = "0100";
$custrefid = "123";
$street = "123 fake st";
$zip = "12345";
$email = "andrew@hostmerchantservices.com"; 


$data = array(
        "GatewayID" => '9238762514',
        "AccountNumber" => $ccNum,
        "RegKey" => '4EXTJST4GKTHPA39',
        "IndustryCode" => '2',
        "ExpirationDate" => $expDate,
        "Amount" => $amount,
        "CustRefID" => $custrefid,
        "Address1" => $street,
        "Zip" => $zip,
        "Email" => $email,
        "GoodsSoldCode" => 'NONE',
        "DeviceType" => '00',
        );

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($data));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, FALSE);

if( ! $response = curl_exec($ch)){
        $response = json_encode(array("0",curl_error($ch)));
}else{
        $response = json_decode($response);
}
curl_close($ch);

var_dump($response);
var_dump($data);
var_dump($ch);
    

Result

string(165) "ResponseCode=05&tranNr=003195506512&PostDate=2019-10-20T16:48:42.000&Amount=000000000100&AmtDueRemaining=0&CardBalance=&Auth=&AVSCode=Y&CVV2Response=&CAVVResultCode=" array(12) { ["GatewayID"]=> string(10) "9238762514" ["AccountNumber"]=> string(15) "371449635392376" ["RegKey"]=> string(16) "4EXTJST4GKTHPA39" ["IndustryCode"]=> string(1) "2" ["ExpirationDate"]=> string(4) "2012" ["Amount"]=> string(4) "0100" ["CustRefID"]=> string(3) "123" ["Address1"]=> string(11) "123 fake st" ["Zip"]=> string(5) "12345" ["Email"]=> string(31) "andrew@hostmerchantservices.com" ["GoodsSoldCode"]=> string(4) "NONE" ["DeviceType"]=> string(2) "00" } resource(2) of type (Unknown)