New user black out map not fog of war.

I'm a new user to roll20, and host a group at my house where we play tabletop, no video cams etc.  I was looking into roll 20 to use for maps for dragonheist campaign I'm running, but I wanted to keep the game personal and not have everyone bring a laptop etc.  I was thinking I could mirror maps from my laptop onto my large tv screen and reveal portions of it as pc's enter areas.  Also use it for monster and pc movement.  But I realized I only see a fog of war option for the gm which would still project onto the big screen and the pc''s could still see the map and underlying tokens just "fogged out".  I was hoping for a completely opaque fog of war setting.  Is there such a thing?  Or is my idea possible?  I just want to currently use the program for the maps, kinda pass the mouse around when it's pc's turns.

This is how it works, it's just that the GM has full vision of course, pc's would see black. The best way to do what you are thinking is to have a second account logged in as a player of the game and they will see just black for the fog of war. Preferably in a different browser or private tab/window. Put the player account on the tv and you as the GM can do whatever you like and keep things hidden as you see fit on your screen.

I actually think may best approach would be to have another player login as a player and mirror their pc

Using Roll20 while Playing In-person  might have some other useful tips for your game. This very suggestion is mentioned on the page, among tings.