I was able to get Eye tracking working with the Quest Pro on PCVR by enabling dev options on the headset and desktop app and turning on eye tracking in desktop.
Then I installed this tool, GitHub - mbucchia/OpenXR-Eye-Trackers: An OpenXR API layer to add eye tracking support for HP Reverb G2 Omnicept and more..
After restarting my PC, I was able to get the eye tracking data from the gaze data blueprint node.