If you want to join a Teams Chat in Keys.Express / Keys Distribution, you need to be invited as a guest (unless you have a keys.express Email address already, then this tutorial is not for you). Provide your email address to IT, so they can invite you as a guest to Microsoft 365 / Teams.
Look out for an email that says xyz has invited you to access application with their organization.
Click the Accept invitation link at the bottom of the email.
Login to your Microsoft account with that email address. If you don’t have a Microsoft account, you can create a free one.
Click “Accept” on the permission to track everything you say or think inside Teams. 😄
Go back to your email inbox; you should see a second invitation to Teams. Click Open Microsoft Teams
Download and Open your Teams app or use Teams online (https://teams.microsoft.com/v2/) and login again if needed.
If you cannot see the Keys Distribution Chat groups #
Go to Organizations with this direct link: https://myaccount.microsoft.com/organizations
You should see Keys Distribution GmbH, this means you joined the organization, that’s good. If you don’t see this, make sure you accept the email invitation from Teams.
In your browser go directly to the Keys Distribution organization and login with your email of the invitation. Enable 2FA.
https://teams.microsoft.com/_?tenantId=752b218e-0434-4a8f-b1bf-ef1f3666a00e
Now you can see the group chats:
