You can add a collaborator to your social account by visiting the TEAM page under MORE... via the main menu at the top of the page.
There are 3 different collaborator types
Manager: A manager is a co-owner for the social account and can perform all the actions that the owner can except invite additional collaborators for the same social account.
Writer: A writer's sole purpose is to add posts to your social account queue for approval i.e The posts will not be published live unless the owner approves them
Helpdesk: A helpdesk user can only perform actions such as Like, Retweet, Reply and Comment on Inbox items. They cannot add posts to the social account queue
To add a collaborator click the Invite a Collaborator button and enter the user's email address.
Note: The Invite a Collaborator feature is only available for the PAID plans