Using ES Module packages in Azure Typescript Function

I am unable to use the package p-map in my Azure Function. I get the following error:

Worker failed to load function: 'serverless' with function id: '<id>'.
Result: Failure
Exception: Worker was unable to load function serverless: 'Error [ERR_REQUIRE_ESM]: require() of ES Module <es-module> from /usr/local/Cellar/azure-functions-core-tools@4/4.0.4483/workers/node/worker-bundle.js not supported.
Instead change the require of index.js in /usr/local/Cellar/azure-functions-core-tools@4/4.0.4483/workers/node/worker-bundle.js to a dynamic import() which is available in all CommonJS modules.'

The project is created by following the steps in Azure's documentation. The following is in the index.ts:

import { AzureFunction, Context, HttpRequest } from "@azure/functions";
import pMap from "p-map";
import got from "got";

const httpTrigger: AzureFunction = async function (context: Context, req: HttpRequest): Promise<void> {
    const sites = [
        'https://avajs.dev',
        'https://github.com'
    ];

    const mapper = async site => {
        const {requestUrl} = await got.head(site);
        return requestUrl;
    };

    const result = await pMap(sites, mapper, {concurrency: 2});
    

    context.res = {
        // status: 200, /* Defaults to 200 */
        body: result
    };

};

export default httpTrigger;

My tsconfig.json looks like following:

{
  "compilerOptions": {
    "module": "es2020",
    "target": "es2020",
    "outDir": "dist",
    "rootDir": ".",
    "sourceMap": true,
    "strict": false,
    "moduleResolution": "node",
    "allowSyntheticDefaultImports": true
  }
}

Lastly, this is my package.json:

{
  "name": "azure-functions-test",
  "version": "1.0.0",
  "description": "",
  "type": "module",
  "scripts": {
    "build": "tsc",
    "watch": "tsc -w",
    "prestart": "npm run build",
    "start": "func start",
    "test": "echo \"No tests yet...\""
  },
  "dependencies": {
    "got": "^12.0.4",
    "p-map": "^5.3.0"
  },
  "devDependencies": {
    "@azure/functions": "^3.0.0",
    "typescript": "^4.0.0"
  }
}

p-map is strictly an ES Module and cannot be used in CommonJS projects.

Am I missing something or is it just not possible to use ES Module packages in Azure Functions? Thanks in advance.

GitHub repository of aforementioned code to test things out locally: azure-functions-test

I resolved my issue by renaming my index.ts file to index.mts. This built a index.mjs file (after running npm run build) in my dist folder which fixed the issue.

One thing to note is that you also have to edit your function.json's scriptFile key so it uses your .mjs file instead of non-existing .js file.