Use Terrain Tags as a method to configure a tile.
Terrain Tags are a numbered value set for the tileset's tiles.
Each tile can have a different value from 0 to 7, the default value being 0.
To change their values, click on the “Terrain Tags” button on the right side of the tileset to enter that mode.
At that point, the tiles will have a number visible on them, most of them at 0 on a new project.
Left-click on a tile to increase their value up to 7, or if already 7 set it to 0, and right-click to lower their value, 0 going to 7.
Setting a tile's Terrain Tag gives it the same configurations you gave that Terrain Tag's number on the Plugin Parameters, then any you add to it through a different method.
This method has a lesser priority, meaning any setting added through this that are changed by another method will be overwritten.
The Terrain Tags' configurations are set on the plugin parameters, nested inside the Tile Config parameters.
Clicking on them, you will open a new window, with the tabs Structure List and Text.
The Text tab we can ignore. It is for setting the value of the whole parameter by putting a text there, but that is a very advanced way to change the values.
Structure List means this is a List, meaning you can add as many as you need, and the elements on the list are a Structure, meaning each one has more parameters to set inside.
The default list has only two elements, but you can either:
Opening one of the values, be it to edit or create a new one, opens a new window, this time with the tab Structure instead of Structure List. These are, basically, parameters, similar to Plugin Parameters but limited to that element of the list. The Terrain Tags' structure has two Values to set: