Scrape password protected sites with RTILA should be easy.
You have two approaches, let me explain the first one because is easier.
RTILA creates an isolated space for each project.
The session information will be stored on the sandbox.
The easiest way to login is, activate the Allow Navigation checkbox (see image below), and log in to the site manually.
The second approach to log in to a site is to create the login automation yourself.
First, clear the cookies.
This will force the login authentication each time you visit the site.
Send the user and password information with the «populate text field» actions, and click the login button.
Create all the other project automation after this step, probably you don’t need further steps to avoid the authentication.