How to set up width of a plot component?

What I’m trying to do:
Display a heatmap with fixed size (in pixel or a fixed width/height ratio). In plot component properties, I can set the height, but I also want to set the width.

What I’ve tried and what’s not working:

  • using data or figures for display
  • update_layout(height=400, width=400)
  • learning from Plotting in Plotly (the clone link seems to be broken)

Clone link: