From the Dashboard, click on Account and select Users from the drop-down.
In the Show Users Section, click on the Email Address of the User.
In the User settings page, click on the Agent Interface Options tab.
Click on Select Agent ACL and select your desired existing settings. You may also click on Create Profile if you want to create a new custom profile.
When using an existing Agent ACL, you may press the Edit Profile button to edit the User Agent Interface Options.
Scroll Down and look for Enable SMS.
Yes = Agent can click on the SMS button and will have the ability to send and receive SMS.
No = SMS Button is hidden from the agent.
Go back to Select Agent ACL and click the Save button to save the updated settings of the User Agent Interface Options.
Scroll down to the bottom and click on Apply Changes.