To use Live Assist for Microsoft Dynamics 365 in a Dynamics 365 Organization with the new Unified Interface, you need to configure the Unified Interface to display the Live Assist Agent Application. You also need to be using the Agent Application version 3.3.0 or above.
See also:
To enable Live Assist when using the Unified Interface:
- Install the Channel Integration Framework (CIF).
See: Getting the Channel Integration Framework - From the Live Assist Setting, copy the Agent Widget URL value.
- Paste the URL into a text editor, and replace the word webclient with unifiedInterface
(in lower case, but with an upper case 'I' for Interface).
For example, the amended URL reads:
https://example.com/agent-widgets/unifiedInterface.html?orgID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx - Open the Channel Integration Framework application
- Create a new Channel Provider record
- Enter the following information:
Field Value to enter Name Live Assist for 365 
Label Live Assist for 365 Channel URL The amended URL from step 3 in this article Enable Outbound Communication Yes Channel order 1 Trusted domain Your organization's URL, for example:
https://example.crm.dynamics.comSelect Unified Interface apps for the channel To display the agent application:
Either:
• Select all apps,
Or:
• Select individual apps
Select the roles for the channel Live Assist Agent 
- Save your entries.