To manage customers in a multi-tenant mode, click the username in the top right corner, then click "Master Panel".
To go back, click "Headwind MDM" in the top left corner, or "Main Panel" in the same place.
In the master panel, you can manage customers and shared applications.
There are basic CRM features (customer status, type, description, etc.).
Shared applications are used to save storage and provide users with most common apps (messengers, maps, etc.).