You just have to send a HTTP GET/POST request to the following URL
URL: https://appyflow.in/api/verifyGST

Parameters to Send
gstNo GST Number whose details are required
key_secret Key Secret will be provided to you by us.

Request must have a Header either
Content-Type: application/json If sending data in JSON format
Content-Type: application/x-www-form-urlencoded If sending data in URLencoded form

JSON will be sent back in response

    {
      "taxpayerInfo": {
        "ctj": "RANGE-IV",
        "pradr": {
          "ntr": "Office / Sale Office",
          "addr": {
            "lg": "",
            "bnm": "",
            "stcd": "Punjab",
            "flno": "",
            "pncd": "141008",
            "city": "",
            "lt": "",
            "dst": "Ludhiana",
            "st": "Street no 1",
            "bno": "3018 Shop no 5",
            "loc": "Ganesh Nagar"
          }
        },
        "tradeNam": "AppyFlow Technologies",
        "lgnm": "DISHANT MAHAJAN",
        "cxdt": "",
        "ctb": "Proprietorship",
        "rgdt": "17/12/2019",
        "adadr": [],
        "dty": "Regular",
        "lstupdt": "17/12/2019",
        "nba": [
          "Office / Sale Office"
        ],
        "stjCd": "PB223",
        "stj": "Ludhiana 3 - Ward No.54",
        "gstin": "03DOXPM4071K1ZE",
        "ctjCd": "ZD0304",
        "sts": "Active"
      },
      "filing": [],
      "compliance": {
        "filingFrequency": null
      }
    }
            }

https://appyflow.in/api/verifyGST?gstNo=GST_NUMBER_HERE&key_secret=KEY_SECRET_HERE

error true If any Error
message Error Message if Error == true else undefined.

There is a Free Quota of 50 requests. So that everyone can get benefits of the api. After that you need to recharge your wallet. If you want more or Have any other query kindly contact AppyFlow Technologies.

To recharge your wallet Click Here

If recharge amount is less than 1000 then 1 Paid Request = 50 Paise
If recharge amount is greater than 1000 then 1 Paid Request = 40 Paise

Example:
For Rs 1000 you'll get 2500 Credits
For Rs 900 you'll get 1800 Credits