1
Context menu

When you are inside your organisation's chat click on the cogwheel next to your organisation name and select "Manage Members".

2
Active Tab

On the next screen you can browse all active users. You can check if they've activated Two-Factor-Authentication and you can remove them.

3
Inactive users tab

This tab shows all your currently invited users that haven't joined the organisation yet and users that have been deleted (but not removed from the database).

4
Teams

Further you can manage your teams from that page.