How to zoom Densitymapbox plot?

I have a Densitymapbox display on a callback. It works.

I am trying to zoom to the appropriate range where the data is located when loading. I’ve tried a few combinations in the layout but I keep having errors.

Here is my example code below. What argument and where do I need to place it, so I can the zoom.

thanks,

Mike

def map_plot(value):
    gps = create_dataframe(value)

    heatmap = go.Densitymapbox(lat=gps .lat,
                               lon=gps.lon,
                               z=gps.av_lat_lon_gps_signal,
                               text=gps ['ul_gps_datetime'],
                  
                               hovertemplate="Datetime: %{text} <br>" +
                                             "average signal: %{z} <br>"
                            
                               ,
                               radius=20,
                               colorscale='tropic',
                               )


    return {'data': [heatmap],
            'layout':  go.Layout(
                mapbox_style="open-street-map",
                mapbox_center_lon=130,
                margin={"r": 0, "t": 0, "l": 0, "b": 0},