I am getting this error any time i call my lambda function. So i am running the API Gateway AWS Proxy test in the AWS Console just to test out the lambda, but i keep running into this error

{
  "errorMessage": "'ResponseURL'",
  "errorType": "KeyError",
  "stackTrace": [
    [
      "/var/task/index.py",
      110,
      "handler",
      "cfn_error(\"invalid request. Missing key %s\" % str(e))"
    ],
    [
      "/var/task/index.py",
      29,
      "cfn_error",
      "cfn_send(event, context, CFN_FAILED, reason=message)"
    ],
    [
      "/var/task/index.py",
      194,
      "cfn_send",
      "responseUrl = event['ResponseURL']"
    ]
  ]
}

My lambda is written in javascript. This is a very difficult problem to figure out since it is giving me the error output in python.

Here is the handler code

exports.handler = async function (event) {
    console.log("request:", JSON.stringify(event, undefined, 2));
    return {
        statusCode: 200,
        headers: { "Content-Type": "text/plain" },
        body: `Hello, CDK! You've hit ${event.path}\n`
    };
};

Here is the lambda initializer

    const hello = new lambda.Function(this, 'HelloHandler', {
      runtime: lambda.Runtime.NODEJS_14_X,
      code: lambda.Code.fromAsset('lambda'),
      handler: 'hello.handler'
    });
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