How to make the plot's title in square and change its background?

I want to make the title of the plot to be inside a box and have a different background color than the rest of the plot. I searched for how to handle this but I couldn’t find any solution so can anyone help me to figure out how to do this?

here’s the code of the plot

var trace1 = {
        type: 'bar',
        x: ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"],
        y: [5, 10, 2, 8, 9, 23, 26],
        marker: {
            color: '#17a2b8'
        }
        };

        var data = [ trace1 ];

        var layout = { 
        title: 'Number of Requests in the last 7 days',
        font: {size: 10}
        };

        var config = {responsive: true}

        Plotly.newPlot('chart', data, layout, config );