Make menu link to login page at wp-login.php

I moved a company’s site to another host. Previous developer and office manager are out of the picture. Site has three dozen plugins. Login link in the menu bar disappeared. Plugins are Theme-My-Login and Place Login. But, I don’t understand how they create the wp-login.php page or work with it. I haven’t found documentation yet explaining how wp-login.php works. The plugin docs assume I know how they work.

How do I recreate a link in the menu to go to wp-login.php?