As an Owner or Admin, you have total control over the Project's access through the Dashboard.
Please mind the steps below in order to invite additional team members.
1. After logging in, click on Settings on the left-hand side
2. Then, select the tab called Team
Now you are looking at the Team that has access to this Project along with their individual Role (permissions).
3. In order to invite a new team member, click on the Send Invite button on the right-hand side of the page
4. Now, you will just need to type that person's email address and select the desired role for them. As soon as a Role is selected, the Dashboard will present the list of Permissions related to it.
5. Voilà! The invite has been sent.