If you have an active GrutBrushes membership you can add and install brushes directly into Photoshop via the GrutBrushes plugin panel using the “New” button.
You may think that it is broken, but it is likely just slow to load. I’m very sorry about that, but with a bit of patience, it is fast once it loads up. This 45 second video shows you how it’s done.
If you don’t see the screen with all the brushes, you can navigate to it in the menu by going to My Account > Members Brush Portal