For added security, Betterment offers its users the ability to create an App-Specific Password. Before you can establish a connection in Simplifi, you'll need to create a password, which can be done by following these steps:
Sign in to the Betterment website.
Go to Settings > Security.
Scroll down to the section called App Passwords.
Follow the steps to create an App Password for Simplifi (Quicken).
If you experience trouble adding your account, please don't hesitate to contact support.