I don't know that this is possible in Lightroom (-Desktop)! I cannot find a command (as there is in Lightroom-Classic.)
A work-around thought is a Screen-clip of Full-screen view. (Greenshot is a good app for screen-clips in Windows.)
Regards. My System: Lr-Classic 12.3 Photoshop 24.5, ACR 15.3.1, Lightroom 6.3.1, Lr-iOS 8.0.8, Bridge 13.0.3, Windows-11.