Trying to make textures read and writeable per pixel

hi, as the title states I’m trying to write to textures per pixel and update them in game.
I found this article on it but I can’t get it working.
I can follow the article just fine until I get at the “Dynamic Texture & Dynamic Material” title.
Here they suddenly use names without declaring them anywhere so I don’t know what to do with them.
Variables like mDynamicMaterials, mDynamicTexture, StaticMeshComponent etc.
I figured out a few of them but some just feel vague.


Any help would be highly appreciated.