Important: Message is being discontinued on October 30, 2020 and is no longer accepting new users. If you did not begin using Message before February, 2020, you will not be able to add it to your Chat account. Additionally, existing Message users can no longer create new Facebook/LINE pages within their account. For more details, see the Zendesk End of Life policy, How much notice will Zendesk give for feature removal?
Agents are created and managed through the Zendesk Chat dashboard, but you can navigate to agents settings page from Message. Agents in Chat have agent permissions in Message, and administrators in Chat have administrator permissions in message.