LumenRT for NVIDIA Omniverse is accessed exclusively through the NVIDIA Omniverse Launcher.
The link to download and install the product: https://www.nvidia.com/en-us/omniverse/download/
Click on "Download Free" and Register yourself to download the launcher.
Choose the operating system and download the launcher.
After it get successfully downloaded please run the downloaded application and create an NVIDIA Omniverse account (Please note the ID and password for future reference).
After opening launcher , Go to Exchange and click on "BENTLEY LUMENRT FOR NVIDIA OMNIVERSE"
Click "Install" for installing LumenRT for NVIDIA Omniverse.
After the installation to launch the application, go to Library (you can see all the installed application over here). Click "Launch".
You can also refer to this video .