Adding users to your Margo dashboard is the best way to collaborate.
In order to invite teammates to your account, you'll need to be sure that you are the company account owner. Navigate to your name in the top right corner, and in the dropdown, select "Company Settings."
This will serve as a home base for managing your account. Here, you'll be able to manage your subscription, update billing, and manage your team members. To invite a new user, click the "Send Invite" button to the right.
You'll then be prompted with a dialog box. Complete the fields and your invitation will be sent. Under "Role", you'll have the option to make the user "Primary" or a "Teammate." Note that your account limits how many primary users you can have on a given account depending on your subscription level.