Polar: Title and Legend sizes are linked!

plotly.js
1

I would like to set two different font family and font size to my Scatter Polar graph, but when I don’t know to to config these 2 independent parameters using Plotly JS.

Here is my code:

let layout = {
        title: {
            text: graphs[0].title,
            x: 0.5,
            xanchor: 'center'
        },
        font: {
            size: 20
        },
        legend: {
            bgcolor: 'rgba(0, 0, 0, 0)'
        },
        showlegend: true,

        polar: {
            radialaxis: {
                tickfont: {
                    size: 25
                }
            },
            angularaxis: {
                linecolor: 'black',
                linewidth: 2,
                mirror: true,
                tickfont: {
                    size: 24
                },
                rotation: -90,
                direction: "counterclockwise"
            }
        }

    }

Following the current online documentation, this should be:

layout.textfont.family
layout.textfont.size

But it doesn’t work!

The only way that I found until now is to use:

layout.font.family
layout.font.size

But in this way I set both title and legend font family and font size with equal values.

How can I set font family and font size to my Scatter Polar graph Title and my graph legend independently?