If you are a user who has been invited by your team administrator to collaborate, go ahead and install the app.
Verify yourself with your email address with the OTP sent to you. You will then have access to look up your other team members, chat with them one-on-on, chat the pre-configured chat rooms, access other micro-apps for purpose built use cases such as tasks, expenses, attendance, forms, discussion groups etc. Also, act on pending approvals, access specific dashboards and more.