I am working on an app for Jira Cloud platform using forge framework. I created an HTTP endpoint using AWS API Gateway. This endpoint triggers a lambda function that does some operation on DynamoDB. I employed IAM authorization for the endpoint. After failing trials to use aws4 library with forge, I used the following function that is taken from AWS documentation to create signing key. However, while sending the request using javascript, I always get "{message: Forbidden}".:

export function getAWSHeaders(){
  const accessKey = ""
  const secretKey =  ""
  const regionName = "us-east-1"
  const serviceName = "execute-api"


  var date = new Date().toISOString().split('.')[0] + 'Z';
  date = date.split("-").join("").split(":").join("")
  var dateWithoutTime = date.split("T")[0]

  var myHeaders = {}
  myHeaders["X-Amz-Date"] = date;

  var crypto = require("crypto-js");

  var kDate = crypto.HmacSHA256(dateWithoutTime, "AWS4" + secretKey);
  var kRegion = crypto.HmacSHA256(regionName, kDate);
  var kService = crypto.HmacSHA256(serviceName, kRegion);
  var kSigning = crypto.HmacSHA256("aws4_request", kService);

  myHeaders["Authorization"] = "AWS4-HMAC-SHA256 Credential=" + accessKey + "/" + dateWithoutTime + "/us-east-1/execute-api/aws4_request, SignedHeaders=host;x-amz-date, Signature=" + kSigning

  return myHeaders;
}

This is how I send the request:

resolver.define("test", async ({context}) => {
  var url = ""
  var myHeaders = getAWSHeaders()
  var requestOptions = {
    method: 'GET',
    headers: myHeaders,
    redirect: 'follow'
  };

  const result = await fetch(url, requestOptions)

I cannot figure out what is wrong with my signing key generation. I checked several posts but could not find a sample request. Thanks for the help in advance.

PS: I tested it using Postman, it works with the "AWS Signature" authorization in Postman.