Step 1: Go to the TMS URL:  

Step 2: Choose an extension account.

Step 3: Click on the Agent menu item.

Step 4: Click on the Agent Workspace sub-menu item.

Step 5: Click on the External Phone client  - A popup will say that it is not installed with a link to download it. 

Step 6: Click on the link that will download the app. Once the app has been downloaded, click on the setup file to start the installation.

Step 7: Ensure the External Phone Client is running in the background  - The External Phone Client icon will show in your PC’s bottom right quick menu.