Create a board instance, enter board name, and submit (click "Save") without an modifications.
The Token and Secret will generate. Click the Sign In Twitter button.
Make sure you are logged in the correct twitter account and click on "Authorize App." Then copy the given pin from the screen, and paste in the Pin field in eQuest. Click Save.
Enter your Twitter username into the Username field and click Save.
If after these steps, an Invalid credentials error is shown, it is necessary to clear all fields (Username, Pin, token and secret) and start all over again.