How can i change the Layer of a legend in plotly?

Is it possible to put the legend of my plot in plotly into the back, so that I can add images on it?

I've already tried to put my image above:

fig.add_layout_image(
    x=1.01,
    y=0.825,
    source=Image.open(png),
    xref="paper",
    yref="paper",
    sizex=0.02,
    sizey=0.02,
    xanchor="center",
    yanchor="middle",
    layer="above")

But it seems that it doesnt work ...