setViewportResolution

Hi All,
i have been trying to use the setViewportresolution , but it seems like it’s not working for me.
I have set up the graph as
12de6ea2dce0a751ea9d3c8be4dfe9d1926c5e18_2_690x478
but the resolution of the viewport is always 1280x720.
How can I change it?
Thanks