But when I look and stream on the 3 TV screens I see that I can delete a movie (or file) from any of the 3 stations there. I want to restrict this. Do I have to create an extra account and activate a plugin to buy this? Or is there a free workaround to protect deleted files when logged in on my Plex account on the 3 Tvs?
Only the admin of the server is able to delete media – and only if you specifically enabled it in your server configuration (Settings > [Server Name] > Library > Allow media deletion).
If you have other members of your family using the TVs under your account, they will have the same permissions/rights. Therefore… if you want to limit them from deleting your media you’ll need to give them their own accounts.
This can be regular Plex accounts or managed users with whom you will then share your libraries. If you’re assigning all of them to your “Plex Home”, you can use fast user switching on the TV.