Add the mean in box plots with plotly express?

I have the following figure:

and I would like to add the mean.

Is it possible with Plotly Express, without using Graph Objects go.Box()?

For information, here is my code:

import plotly.express as px
fig = px.box(device_field_strength_impact_df, 
	    y='value',
		x='device_field_strength', 
		color='variable', 
		# boxmean=True,
		facet_col='group',
		)
fig.show()

and the pandas DataFrame:

method	group	patient	device_field_strength	variable	value
expert1	experts	62	device_field_strength_1.5	F1_score	0.857
expert1	experts	66	device_field_strength_3	    F1_score	0.909
...	...	...	...	...	...	...

Note: I made the same figure with Graph Objects but I don't know how to handle the legend and x labels.

You can create empty plot and then set parameters for boxplot using fig.update_traces, including mean:

import plotly.express as px

fig = px.box()

fig.update_traces(
    # box
    q1=[1, 2, 3], 
    median=[4, 5, 6],
    q3=[7, 8, 9], 
    # fences
    lowerfence=[-1, 0, 1],
    upperfence=[10, 11, 12], 
    # mean and std
    mean=[2.2, 2.8, 4.2],
    sd=[0.2, 0.4, 0.6], 
    notchspan=[0.2, 0.4, 0.6],
    
    boxpoints=False
)

fig.show()

Not the most convenient method (you have to calculate values separately), but looks like it works.

As @r-beginners answered in his comment:
> You can add the averages by adding fig.update_traces(boxmean=True) after the px.box().

Indeed, the following code works perfectly:

import plotly.express as px
fig = px.box(device_field_strength_impact_df, 
        y='value',
        x='device_field_strength', 
        color='variable', 
        facet_col='group',
        )
fig.update_traces(boxmean=True)
fig.show()