I am using node js to integrate PayTm “Create qr api” with the approch mentioned here -> “https://business.paytm.com/docs/api/create-qr-code-api/”

My code –

const Paytm = require('paytmchecksum');
const express = require('express');
const https = require('https');

const createQr = async (req,res) => {
    const paytmParams = {
        body: {
            "mid": process.env.PAYTM_MERCHANT_ID,
            "orderId": req.body.orderid, 
            "amount": `${req.body.amount}`,
            "businessType": "UPI_QR_CODE",
            "posId": "S12_123"
        }
    };

const checksum = await Paytm.generateSignature(JSON.stringify(paytmParams.body), process.env.PAYTM_SECRET_KEY)
    console.log(checksum)
    paytmParams.head = {
        "clientId": "C11", // Replace with your client ID
        "version": "v1",
        "signature": checksum
    };

    const post_data = JSON.stringify(paytmParams);
    const options = {
        hostname: 'securegw.paytm.in',
        port: 443,
        path: '/paymentservices/qr/create',
        method: 'POST',
        headers: {
            'Content-Type': 'application/json',
            'Content-Length': post_data.length
        }
    };



    const post_req = https.request(options, function (post_res) {
        let response = '';
        post_res.on('data', function (chunk) {
            response += chunk;
        });

        post_res.on('end', function () {
            console.log('Response:', response);
            res.json({ qrCodeResponse: JSON.parse(response) });
        });
    });

    post_req.on('error', function (error) {
        console.error('Error:', error);
        res.status(500).send('Error generating QR code');
    });

    post_req.write(post_data);
    post_req.end();

}

The response i am getting –

Response: {"resultInfo":{"resultStatus":"403","resultCodeId":null,"resultCode":null,"resultMsg":"Unauthorized Access","retryable":false}}

I tried using diff test merchant id’s and keys but it is not solving the problem