Tilt Brush has been dead for over two years.
> The open source archive of the Tilt Brush code can be found at: https://github.com/googlevr/tilt-brush. Please note that it is not an actively developed product, and no pull requests will be accepted.
https://opensource.googleblog.com/2021/01/the-future-of-tilt...
Note that TiltBrush (from Google) recently went open source as they stopped developing it directly: https://github.com/googlevr/tilt-brush I saw some active forks already, but haven't yet tried it (would like a nice Linux build).