Background image Scatter Polar Plot in Javascript


I have a locally accessed web app running on IIS server. My javascript Plotly scatter polar plot is working well, but I have been asked to add a background image to the graphs. To test this, I added images to my layout variable:

            var data = [meanPoint, limitPoints, passPoints, failPoints];

            var layout = {
				showlegend: true,
                font: { size: 15, family: "Arial", color: "rgb(0,0,0)"},
				autoexpand: true,
                height: 400,
                width: 400,
				title: 'Static',
                radialaxis: { range: [0, rangeLimitMax]},
				direction: 'counterclockwise',
					radialaxis: { linecolor: 'black' }
				images: [
						  x: 0.5,
						  y: 0.5,
						  sizex: 0.5,
						  sizey: 0.5,
						  source: "",
						  xanchor: "center",
						  xref: "x",
						  yanchor: "middle",
						  yref: "y",
						  sizing: "stretch",
            Plotly.plot(divName, data, layout);

However, no background image appears. Any input or suggestions? Iā€™m pretty new to Plotly.