Lambda Function Error

I created Lambda function(Node.js) for image resizing. I got Runtime.HandlerNotFound error.

Cloudwatch log as follows:

2022-07-15T01:06:22.016Z undefined ERROR Uncaught Exception { "errorType": "Runtime.HandlerNotFound", "errorMessage": "index.handler is undefined or not exported", "stack": [ "Runtime.HandlerNotFound: index.handler is undefined or not exported", " at Object.module.exports.load (/var/runtime/UserFunction.js:283:11)", " at Object.<anonymous> (/var/runtime/index.js:43:34)", " at Module._compile (internal/modules/cjs/loader.js:1085:14)", " at Object.Module._extensions..js (internal/modules/cjs/loader.js:1114:10)", " at Module.load (internal/modules/cjs/loader.js:950:32)", " at Function.Module._load (internal/modules/cjs/loader.js:790:12)", " at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:75:12)", " at internal/main/run_main_module.js:17:47" ] }

Some of my Index.js is as follows:

'use strict';

const querystring = require('querystring'); // Don't install. const AWS = require('aws-sdk'); // Don't install.

// http://sharp.pixelplumbing.com/en/stable/api-resize/ const Sharp = require('sharp');

const S3 = new AWS.S3({ region: 'ap-northeast-2' // });

const BUCKET = 'BUCKET_NAME' // Input your bucket

// Image types that can be handled by Sharp const supportImageTypes = ['jpg', 'jpeg', 'png', 'gif', 'webp', 'svg', 'tiff', 'jfif'];

exports.handler = async(event, context, callback) => { const { request, response } = event.Records[0].cf;

console.log("request: ", request) console.log("response: ", response) . . . .