Can't seem to authenticate with Cognito

[kmoec]

I'm trying to incorporate Cognito authentication into my React based project. My code is based on examples given in NPM page. This is what it looks like :

import { CognitoUserPool, CognitoUser, AuthenticationDetails } from 'amazon-cognito-identity-js';    
var authenticationData = {
    Username : 'username',
    Password : 'password',
};
var authenticationDetails = new AmazonCognitoIdentity.AuthenticationDetails(authenticationData);
var poolData = {
    UserPoolId : '...', // Your user pool id here
    ClientId : '...' // Your client id here
};
var userPool = new AmazonCognitoIdentity.CognitoUserPool(poolData);
var userData = {
    Username : 'username',
    Pool : userPool
};
var cognitoUser = new AmazonCognitoIdentity.CognitoUser(userData);
cognitoUser.authenticateUser(authenticationDetails, {
    onSuccess: function (result) {
               console.log('Successfully logged!');
            }
        });
    },

    onFailure: function(err) {
        console.log(JSON.stringify(err));
    },

});

I have created a user pool and added an app client. I have also enabled identity provider for app client. However, my code fails to authenticate with error {"code":"NetworkError","name":"Error","message":"Network error"}. Since my project is still hosted on localhost, I have installed CORS plug-in for firefox, but that doesn't resolve the issue. Does anyone familiar with this error and know how to fix it?

[kmoec]

Sorry, didn't mean to post here. Wrong library.