To set the "Directory of Users" option in your Softphone, please follow the steps below:

Copy the link and modify it to fit your needs as shown in step one:
https://<servername>.squaretalk.com/Integration/softphone_api.php?ext=<extensionnumber>
(Where <servername> is your domain name and <extensionnumber> is the number of the extension you are using)
1. Prepare your link as shown here:
2. Go to the top right corner of your softphone and click on the "Menu" button (three stripes)
Choose the "Settings" option from the dropdown menu
3. Paste your modified link in the "Directory of users" field and click "Save" as shown in the image below:
You are all set!
All the available statuses and users should now appear in your softphone.
You can now call your colleagues and change your statuses with a simple double-click on the desired name or status shown in your Directory: