Vdb Forge - Smoke & Dust
The download files contain a pdf with detailed documentation.
If you do not have access to the Internet after installing the addon, you can find the documentation in your addon directory of Blender.
If you still have any questions, please first look at the FAQ. I always update it.
In the case, that even the FAQ could not help you with your problem, feel free to contact me! I'm sure, we can work it out!