How to Have Only The Originator Player See Their Drawings/Text?

I want to be able to have it so that only the player who makes the marks on the map can see them. We are running a map in complete darkness and perception of the fight is going to be based off them each individually taking notes on what they believe is happening around them and where the other creatures are. How do I make it so only they can see their markings?

The only thing you could do is create a transparent token with an aura set up so that only the controlling player can see it, then assign that to a Marker character for each player, which they could then drag onto the map to mark things for themselves.  I'd suggest color coding them so that you can tell the difference between them. There isn't any other way of placing something on the map that only a given player can see.  You could split the party so that each one is on their own separate duplicate copy of the map.  That starts to get into a bit of a logistical nightmare though.