This members-only tutorial provides the steps to add a Login link (for anonymous visitors) link or a Logout link (for already logged in users) as the last menu item in a specific WordPress navigation menu.
For visitors:
For logged in users:
Step 1
Since we want to target a particular nav menu, we need to first obtain its ID.
Go to Appearance > Menus, switch to your menu (if there are multiple) and inspect the nav menu header with browser dev tools.