Login to your Exotel account and click on "Co-workers & groups" tab on the left and "Invite Co-workers" button on the top right as shown below:
You can also enable the agent as ADMIN if you wish to.
For the verification- Once you add them, do not forget to give missed call from the agent’s phone to the number displayed in the note.
For the new user, password link would be sent out on the email they have registered in it.
Note that the default number of co-workers (maximum) that could be added is 50 and in case you wish to be able to add more, please reach out to our support team at 8088919888 or write to us at email@example.com and we shall assist you henceforth.
Video reference attached.