@jola68 not sure of the question, but HLS is just the protocol that Meraki MV leverages such that you can view and interact with the video and it's completely browser-native, no special software, no broswer plug-ins, or any special settings. This would be unrelated to any HTTPS requirements that might exist on the Intranet. When you are actually viewing the video in the Meraki Dashboard (leveraging HLS) you are in fact looking at it over an https://nxxx.meraki.com/rest-of-the-url web page. Perhaps that was the question, if this is delivered over HTTPS, and it is.
MV is very high security in the first place (encrypted at rest, encrypted in transit, encrypted management traffic) and leverages all of the security mechanisms of the Meraki Dashboard itself, including things like 2-factor authentication and other security mechanisms for your camera administrators (like password complexity requirements, account lockouts, restricting login IP ranges, etc.) Hope that helps. Let us know if we misunderstood the question.