How to use the dotenv.default.config function in dotenv

import { describe, it } from 'mocha';
//import { expect } from 'chai';
//import supertest from 'supertest';
import integration from './_integration.spec-int.js';
import githubUtils from '../src/serverless/gtmGithubUtils.js';
import { default as json } from 'format-json';
import { default as firstline } from 'firstline';

import { default as util } from 'util';
import { default as dotenv } from 'dotenv';

dotenv.config();

describe('GitHub Task Manager', () => {
    describe('should correctly update a pull request', () => {
        /**
         * 1. fork github repo from template at github.com/zotoio/gtm-test
         * 2. add webhook with secret
         * 3. create a branch
         * 4. create a file
         * 5. open a pull request back to master
         *
         */

        //console.log(integration);
        //let request = supertest(integration.urlPrefix);

        it('should trigger behaviors if hostname matches exactly', async () => {

import { default as dotenv } from 'dotenv';
dotenv.config();

import { Agent } from './Agent';

(() => {
    let agent = new Agent();
    agent.start();
})();