A user's login key allows him to edit his personal form as well as to connect to the Signitic desktop application.
❶ Access the user menu
To copy the login key, go to the Users menu.

Then select the desired user.
❷ Copy the login key

In the Settings tab, you will find the Login Key.
Just click on the Copy button: a confirmation message will appear at the top right of your screen.
You can also send this key to a predefined user population using the method described in this article.