Inviting someone to a roadmap does not automatically add them to your team plan. Editors can invite others to view or edit their roadmaps, however only the team administrator can invite a new person to join a team plan.
To invite someone to just a roadmap, click ‘Share’ on the menu to the right. From there, you can invite someone by email address to view or edit that roadmap. Editors require a paid license, but viewer accounts are free.
As a team administrator, inviting someone to join your plan does not automatically give them access to your roadmaps as well. Once added to your plan, you can share roadmaps with your whole team, or individually. You can manage licenses from your Manage Team page, as well as invite new users.