Allow Anonymous Users through Security Settings and define a (custom) Sign in page in your Navigation.
A sign-in page can be made with the widgets available in the connector:
- Login id textbox
- Password textbox
- Sign in button
Additionally you can also resort to changing the login.html in your Theme folder (Project Directory) with your HTML/CSS skills (default login page has its own css file..)
Take a look at the Login Form widget available on the app store.
And also the instructions on the first result here:
Yes, your theme folder (/projectfolder/theme) contains a login.html file. You can edit that to style your login page. You can find the login.css file in /projectfolder/theme/styles.