There is no option to consult users connected to the LRE 2020 Portal.
In previous versions as a part of ALM this option was available through - Site Connections.
There was an internal messaging service - Send message that allowed you to write DIRECTLY to the connected users by selecting them.
It is useful to be able to notify the connected users before for example having to stop the service.
Would it be possible to have similar functionality in LRE?