To use Twitter bar and other Twitter related widgets, you need OAuth access keys. To get Twitter Access keys, you need to create Twitter Application which is mandatory to access Twitter.
To get these, please follow the steps below:

-Go to https://apps.twitter.com/app/new and log in, if necessary
-Enter a Name, Description and your website address, for your Application. You can leave the callback URL empty.
-Accept the TOS, and solve the CAPTCHA.
-Submit the form by clicking the Create your Twitter Application
-Copy the consumer key (API key) and consumer secret from the “Keys And Access Tokens” tab, into your application

Copy those keys and paste in our Theme Options page. That’s it. Now Your Twitter account will get tweets and display them in your theme.