Steps to Connect to Fitbit:
In the main screen, click the Menu icon
Select Settings, then click on connections from the options.
From the Connection section, scroll to find the Fitbit option and click on Connect.
You will be directed to your Fitbit account login, input your credentials and click on Login. Please make sure you accept the Permissions that Fitbit list.
When you get a notification saying "Open this page in The Conqueror" click on "Open".
Your app should then show as connected.
Here are the above steps in action: