A7iii viewfinder is not working, I can’t see nothing from it...

[Drifting_Cloud]

What’s is the problem? I am new to this camera, watched so many videos to find the issue, but seemed no one had this issue like mine. Is the setting wrong? Help ! 

[Strampke]

You did find:  MENU  -> (Camera Settings 2)  -> FINDER/MONITOR  in the Manual?

And of course there is Sony video on Youtube.