How to use the Zoho Desk Invoke API (Proxy) to call the Zoho Desk Push-Data to Desk (aka Import) endpoint?

I am trying to use the Zoho Desk Invoke API (Proxy) to call the Zoho Desk Push-Data to Desk (aka Import) endpoint.

This is what my code looks like:

// Build the payload
const invokeApiRequestPayload = {
   "securityContext":"edbsnc50b85a3cd964126073f50499ae29a3d6ed3c31123e535e901cdda1b2a312dc0a66c638e2beb2724fffc355faebabf1acd65c3883227c2d329d0c9f62cbbdf26ba4553375b5b11cab90c57590c6b48a3",
   "requestURL":"https://desk.zoho.com.au/api/v1/channels/{{installationId}}/import",
   "headers":{
      "Content-Type":"application/json"
   },
   "postBody":{
      "data":{
         "tickets":[
            {
               "actor":{
                  "email":"test@gmail.com",
                  "name":"Tom Billy",
                  "extId":"NjPk2E6J83g41uDKsD6DznLzz323"
               },
               "subject":"testing new ticket",
               "createdTime":"2022-07-24T01:13:44.419Z",
               "status":"Open",
               "extId":"YCdHTnu93pQbyNoyZzId"
            }
         ],
         "threads":[
            {
               "contentType":"text/html",
               "createdTime":"2022-07-24T01:13:44.419Z",
               "extId":"YGrfU6quGoDESjX5HEZM",
               "extParentId":"YCdHTnu93pQbyNoyZzId",
               "actor":{
                  "extId":"NjPk2E6J83g41uDKsD6DznLzz323",
                  "name":"Tom Billy",
                  "email":"test@gmail.com"
               },
               "canReply":true,
               "content":"testing one two three<br>"
            }
         ]
      }
   },
   "connectionLinkName":"zohodesk",
   "requestType":"POST",
   "queryParams":{
      "orgId":"7002257443"
   }
};

// Generate the Hmac
const stringToHash = 'requestURL=https://desk.zoho.com.au/api/v1/channels/{{installationId}}/import&requestType=POST&queryParams={"orgId":"7002257443"}&postBody={"data":{"tickets":[{"extId":"YCdHTnu93pQbyNoyZzId","status":"Open","subject":"testing new ticket","createdTime":"2022-07-24T01:13:44.419Z","actor":{"extId":"NjPk2E6J83g41uDKsD6DznLzz323","name":"Tom Billy","email":"test@gmail.com"}}],"threads":[{"extId":"YGrfU6quGoDESjX5HEZM","extParentId":"YCdHTnu93pQbyNoyZzId","actor":{"extId":"NjPk2E6J83g41uDKsD6DznLzz323","name":"Tom Billy","email":"test@gmail.com"},"content":"testing one two three<br>","createdTime":"2022-07-24T01:13:44.419Z","canReply":true,"contentType":"text/html"}]}}&headers={"Content-Type":"application/json"}&connectionLinkName=zohodesk';

const hmac = crypto
  .createHmac('sha256', 'mysecret123')
  .update(stringToHash)
  .digest('hex');
// The hmac created from the above code is '2aa21d41882223e2e23ad7004cfdc5a0317db5192fdff84431f0515d4f4e004b'

// Make the Invoke API request using Axios
const axiosOptions = {
  headers: {
    'Content-Type': 'application/x-www-form-urlencoded',
    hash: hmac,
  },
  params: {
    orgId: '7002257443',
  },
};

return await axios
  .post(
    'https://desk.zoho.com.au/api/v1/invoke',
    invokeApiRequestPayload,
    axiosOptions
  )
  .catch((error) => {
    functions.logger.error(error);
    throw new functions.https.HttpsError('unknown', error.message, error);
  });

But I always get back Error 422 UNPROCESSABLE_ENTITY:

{
   "errorCode":"UNPROCESSABLE_ENTITY",
   "message":"`Extra query parameter '{\"securityContext\":\"edbsnc50b85a3cd964126073f50499ae29a3d6ed3c31123e535e901cdda1b2a312dc0a66c638e2beb2724fffc355faebabf1acd65c3883227c2d329d0c9f62cbbdf26ba4553375b5b11cab90c57590c6b48a3\",\"requestURL\":\"https://desk.zoho.com.au/api/v1/channels/{{installationId}}/import\",\"requestType\":\"POST\",\"postBody\":{\"data\":{\"tickets\":[{\"extId\":\"YCdHTnu93pQbyNoyZzId\",\"status\":\"Open\",\"subject\":\"testing new ticket\",\"createdTime\":\"2022-07-24T01:13:44.419Z\",\"actor\":{\"extId\":\"NjPk2E6J83g41uDKsD6DznLzz323\",\"name\":\"Tom Billy\",\"email\":\"test@gmail.com\"}}],\"threads\":[{\"extId\":\"YGrfU6quGoDESjX5HEZM\",\"extParentId\":\"YCdHTnu93pQbyNoyZzId\",\"actor\":{\"extId\":\"NjPk2E6J83g41uDKsD6DznLzz323\",\"name\":\"Tom Billy\",\"email\":\"test@gmail.com\"},\"content\":\"testing one two three<br>\",\"createdTime\":\"2022-07-24T01:13:44.419Z\",\"canReply\":true,\"contentType\":\"text/html\"}]}},\"headers\":{\"Content-Type\":\"application/json\"},\"queryParams\":{\"orgId\":\"7002257443\"},\"connectionLinkName\":\"zohodesk\"}' is present in the input.`"
}

The Zoho Desk docs have this explanation for the UNPROCESSABLE_ENTITY error code:

This errorCode value appears if the input does not fulfil the conditions necessary for successfully executing the API.

And looking at the returned error message details it seems to be complaining that I have an "Extra query parameter". That does not make sense to me, because I included it as the payload required by the Zoho Desk Invoke API (Proxy).

Can anyone see what I am doing wrong?