The Toolkit Twitter Control uses Twitter API v1.1. The Twitter API v1.1 which is required to provide API keys which are Consumer Key, Consumer Secret, Access token and Access token secret.
You will need to create those keys through https://dev.twitter.com/apps/new and supply those information into
your web config under appSettings tag. It should looks like this:
<appSettings>
<add key="act:TwitterConsumerKey"
value="[Your consumer key]"/>
<add key="act:TwitterConsumerSecret"
value="[Your consumer secret]"/>
<add key="act:TwitterAccessToken"
value="[Your access token]"/>
<add key="act:TwitterAccessTokenSecret"
value="[Your token secret]"/>
</appSettings>
For more information about Twitter API v1.1 you can find in
https://dev.twitter.com/docs/api/1.1/overview.