getEncryptedOrder function not working

[theharshguptaflutter]

when i encrypt my data its automatic adding merchant_id including in output

request
const enc_request = {
reference_no: "313010796924",
refund_amount: amount.toFixed(2),
refund_ref_no: "API1234",
};
this output i getting i don't know how it automatic merchant_id added on response

Decrypting the response from CCAvenue to a JSON output
{
merchant_id: '2944774',
reference_no: '313010796924',
refund_amount: '15998.00',
refund_ref_no: 'API1234'
}

help me