Unifi is exclusively available through the ServiceNow Store with a limited trial or paid subscription.
To install Unifi on your instance, you will need to ensure it has been given entitlement to the application. You must do this through the ServiceNow Store.
Once you have setup entitlement, you can use the Application Manager in your ServiceNow instance to install Unifi. You can find more information on how to Install a ServiceNow Store Application in the ServiceNow Product Documentation.
2. Install Global Utility
Unifi has some powerful features that will only work with access to the global scope. Access is granted through the Unifi Global Utility.