Launch the application from Exchange Store Menu (Refer screenshot - Menu)

Assign desired effect IDs to objects and materials.

Create Render Elements by pressing the button "Create Render Elements"

For rendering mask for selected objects use the rollout "Render Mask for Selected nodes" - this ability now only available for V-Ray

The installer that ran when you downloaded this app/plug-in from Autodesk App Store will start installing the app/plug-in. OR, simply double-click the downloaded installer to install the app/plugin. You may need to restart the Autodesk product to activate the app/plug-in.

To uninstall this plug-in, exit the Autodesk product if you are currently running it, simply rerun the installer, and select the "Uninstall" button. OR, click Control Panel > Programs > Programs and Features (Windows 7/8.1/10/11) and uninstall as you would any other application from your system.