hi
does it work if you do
$ orca graph "{ \"data\": [{\"y\": [1,2,1]}] }" -o fig.png
in the terminal window ?
The thing is that i have never managed to make this save image function work on windows and on mac. So i went around by using this function in Jupyter like that
call([‘orca’, ‘graph’, json.dumps(name_of_your_figure, cls=plotly.utils.PlotlyJSONEncoder), ‘-o’, ‘name_of_your_output_file’,’-d’,‘images’,’-f’,‘svg’])
it works most of the time but the problem is that sometimes it will not save the image because for some reason it considers the image too big
(error message in that case is the misleading
“FileNotFoundError: [WinError 206] The filename or extension is too long” )
Then I have found other people with the same problem on the forum and asked them if they found the solution and never did and had to give up on plotly.
not exactly the most secure set up if you have to rely on it 
I believe unfortunately that it is close to hopeless.
Good luck