This video tut is made in an older version of Photoshop, so small things differ a bit.
1. In the latest Photoshop version, the Tree generating option moved to Filter > Render > Tree.
2. In the new Photoshop you can change the color of the tree into black by clicking on the tap called advanced inside the “three window” and change the leaves and branches colors to black. But actually, it’s not necessary. The brush you make afterwards will work anyway.
3. If the option to define a brush pre-set isn’t possible try one of these solutions.
– set down the size of the tree.
– check if your GPU is activated in Photoshops preferences > performance