In Blender 2.8 navigate to Edit > Preferences.
In the Preferences window click the Add-ons tab.
Now click Install and select the install file you downloaded (.zip) to install it.
The addon is now setup.
You'll find a new option in your File > Export .. menu specifically for Previz.
When you're ready to move your scene to Previz, just click the Previz option and then visit the main Previz app and upload the updated version in the project's Scene Config area.
Now that the Previz addon is enabled read how to prepare your scene for upload.
Released on Jan 9, 2017