Cannot paint roads from tutorial

I am new to Core, I started to follow a tutorial about terrain

I have a background in Python and Godot, but always wanted to dive into 3D games, but my lack of graphics design always stopped me, so I am excited to learn Core. However, when I get to the 2nd of 3 videos:

it tells me to go to terrain, click "Paint" and, in the video, it seems to do what the creator wants, but for me, it wipes out the "Grass" off of my generated terrain. I did notice that before i click on "Create new" in Paint, above in red, it says "Cannot paint on this canvas"??
I restarted and follwed along EXACTLY 3 times now and it is just not letting me.. any ideas as to what I am doing wrong??

Hello,

Maybe the "erase foliage" modifier is activated

Select a different material under "materials" in order to desactivate "erase foliage" :

Change Modifier