CORS error on React app with Active Directory plugin

I am getting error 401 or CORS related error when fetching the [Active Directory plugin through its own plugin for React (React-ADAL).

I have to integrate the Active Directory Web API plugin with my React.js App to be able to fetch data from my Microsoft Dynamics 365 CRM platform.

According to Micosoft documentation the ADAL plugin facilitates this CORS stuff but I still see this CORS error while fetching with adalApiFetch() function.

This is my adalConfig.js file:

import { AuthenticationContext, adalFetch, withAdalLogin } from 'react-adal';

export const adalConfig = {
    tenant: '<tenant id>',
    clientId: '<active directory app id>',
    endpoints: {
        api: '<active directory app id>'
    cacheLocation: 'localStorage',

export const authContext = new AuthenticationContext(adalConfig);

export const adalApiFetch = (fetch, url, options) => adalFetch(authContext, adalConfig.endpoints.api, fetch, url, options);

export const withAdalLoginApi = withAdalLogin(authContext, adalConfig.endpoints.api);

And then my Component code to fetch with the plugin:

import React, { Component } from 'react';
import { adalApiFetch } from '../../../adalConfig';

export default class AComponent extends Component {
    componentDidMount() {

    getLeads() {
        let result;
        let headers = new Headers();
        headers.append('Content-Type', 'application/json');
        const options = {
            method: 'GET',

        adalApiFetch(fetch, '', options)
        .then(response =>{
        .catch(error => console.error('SERVER ERROR:', error));

My Chrome's developer tools displays:

Any ideas to fix this? Thanks in advance.