How to restrict users from accessing Agent Desktop?

Summary:
Restricting access to Agent Desktop or end-user pages
Content (required):
We need to implement restrict IP - "which mean to avail the service to specific IP's only from the Work location" as a mandatory security control.

Appreciate to provide steps about how to implement this feature
Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):