[quote=“George, post:6, topic:12868”]
I don’t know how LR can send the image back.[/quote]
The DPL installer installs the necessary plugins in Lightroom. They communicate with DPL in order to send the RAW file to and receive the DNG/TIFF/JPEG file from DPL. This is not only a matter of sending and receiving files, though. Additional code is needed to allow repeating the roundtrip as often as needed without losing settings. That’s the nice thing with this unique feature.
Unfortunately, not all users are aware of this possibility which is described here :
https://www.dxo.com/project/workflow-dxo-photolab-lightroom/
https://www.dxo.com/fr/project/workflow-dxo-photolab-lightroom/