First of all please follow this link to download the Telephone app by 64 Characters (this app is only available on Apple Mac);
Once downloaded go to System Preferences and then to Accounts.
Enter the details as provided by your account manager into the relevant fields displayed
Example:
Name: 'Your Name'
Domain: phone.plivo.com
User Name: EP12345678910
Password: 12345678910
Then press done.
You will see a new small window opens.
Dial your preferred number and press the ENTER key on your keyboard to activate a call.
When finished press the x to close the window in the top left corner.
