To add members to your organization start by selecting the dropdown at the top left of your screen and then select .
You can then select the tab on the left and then move to the tab, then click the button.
A panel will open to allow you to add the email addresses of your colleagues. You can assign roles to them, depending on if you want them to be organisation admins. Finally click the button.
Your colleagues will get emails inviting them to create accounts and join your organisation.