How do I create a group chat?

When you create a group, you can decide in the group settings whether you also want to activate a chat for the group.

1. Click on the menu item "Groups" 
2. Select the group to which you want to add a group chat.
3. Go to the settings of the group
4. Click on the "Chat" field
5. Activate the chat with the slider
6. You will now find the option Group chat in the left menu bar of your group

If you want to start a chat with several people without creating a group, you can start a mutlichat. You can find out how to do this here.