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: Log Into the Agent Workspace.

Step 6: Click on the phone icon to open the dial pad and make a call.

Step 7: Click on the Volume icon to adjust the volume OR Click on the Mute Icon to mute yourself on the call.