This device shows as
534d:2109 MacroSilicon USB Video in lsusb.
Works perfectly! This is the verified solution to use this card:
ffplay -f video4linux2 -framerate 50 -video_size 1920x1080 -input_format mjpeg /dev/video0
If it's not working in OBS studio, try switching
Video Format some times, or manually switch its Resolution to 1920x1080.
If it's still not working, refer to this guide. (The bug in this guide was already fixed in latest kernel, but give it a try. )
It works out-of-box, but with very poor performance. The image is very blur and unusable.