How do I tell FF to "remember this site" to do auto-login?
When I first sign up for a site requiring login credentials, there is a popup saying "remember this site?" or some such. How do I call that at a later time, when I'm using the site & logged in?
Alla svar (2)
When you return to the login page of that site, the Password Manager should load the data for you.
Type about:preferences#security<enter> in the address bar. Look under Logins,
Note: For Firefox v56+ its; about:preferences#privacy Look under Forms & Passwords +++++++++++++++++++++++++++++++ Turn on Remember Logins. To check the passwords you have listed, press Saved Logins.
Press the Exceptions button and see what's inside.
Warning: There are some web pages that do not allow
browsers to record or fill in the log-in information.
Firefox shows the Key icon at the left end of the location bar when it detect a login form, so you can look for this icon.
Note that there is "Fill login" and "Fill Password" in the right-click context menu that you can use if Firefox doesn't fill this data automatically.