You can see here how you can sign up in Engagement Builder.
Since Engagement Builder is built using Twitter OAuth v1 we need certain permission in order for the app to work. Those permissions are Read and Write.
The first permission will allow us to read your tweets and present them to you, see your audience, access your lists, etc.
The write permission allows us to send your tweets, replies and mentions, to Twitter and publish them for you.
Once you click/open the link we will ask you to grant us those permissions. We will ask you to do that only once, unless you change your computer, delete your cache, change your browser, and similar situations. Why? Because the app will not have the access to created cookies. (If you want to read more you can visit our Privacy Policy and Terms of Service pages).
If you decide not to grant us those permissions, unfortunately, we are unable to provide you with our service because it heavily depends on those permissions.
Once granted you’ll be redirected to our app and you’ll see quick onboarding info and you’ll be able to pick the most interesting topics for you. After that you can start using it immediately.