Q.What type of plaster would you put over screening to patch a hole in a tree
What type of plaster would you put over screening to patch a hole in a tree? The tree is a white oak and has a rotten area near the base. The reminder of the tree is healthy. I want to follow your advice on patching the hole with screening but don’t know what to cover the screen with.

Our article is trying to present a number of different views. There are different opinions on how to deal with holes in tree trunks, as approaches to this problem have changed over the years. This article has more information: https://www.gardeningknowhow.com/ornamental/trees/tgen/patching-tree-hole.htm
One thing you should do is find out why the tree trunk has a hole in it. If it's truly rotten, rather than an injury, there could be a disease that needs to be dealt with, for example, https://www.gardeningknowhow.com/plant-problems/disease/alcoholic-flux-in-trees.htm
You might want to have a licensed arborist look at the tree before you do anything else. Of course, basic good care is always the starting point.
If you believe that you want to use the screen and plaster method, any kind of outdoor construction plaster would be what you would use.