How to pass custom params? Because not receiving same in response .

[vishuym]

Hello , before runTransaction I added custom params/data fields,
but not receiving them back in response,

$definedData = new \stdClass();
$definedData->field1 = "123";
$definedData->field2 = "ABC";
$definedData->field3 = "4";
$request->MerchantDefinedData =$definedData;

Do help me on this.

Thanks in advance.