This policy setting specifies the Learning Management System's (LMS) host URL. Some LMS have static host URLs while others have host URLs that are specific to a school or a district. Depending on which LMS the add-in has been configured with, this policy setting may or may not be needed. For more details, please refer to https://aka.ms/classnotebookaddingrouppolicy.
If this policy is enabled, users will not be prompted to enter the host URL when they connect the Class Notebook Add-in for OneNote to the LMS that the add-in is configured with. Instead, the host URL will be obtained from this policy setting, allowing an administrator to control its value for an entire school or district. This also makes it easier to update the LMS host URL should its value change.
If this policy is disabled or not configured, the Class Notebook Add-in for OneNote will prompt the user to enter the host URL. Should the URL change, users will have to manually change its value in the add-in.