Any meeting room a teammate sets up is, by default, team-only.
It's easy to change:
- Here's how to lock a room, or make it public
- If a room is locked, it means guests have to knock, and the team owner has to let them in
- If a room is public, anyone can click on the link, and join. Anyone in the world.
- If a room is team-only, only teammates can join.
By the way, no one has to download anything. For example, with a locked room, a guest clicks on the link, and then knocks and waits for the host. There's no download to make the request to join.