Probleme with date label when i try to export plotly graph

[Jacques2101]

Hi

when i try to generate this toy data i have the date that are (huge) number and not date whereas it should be...
I tried many thinks to change this point but no way, it was impossible!
Any help would be helpful

I am using :

• Plotly 6.2.0
• Kaleido 1.0.0
• Python 3.13.5

import pandas as pd

import numpy as np
import plotly.express as px

# Generation of df 
dates = pd.date_range(start="2020-01-01", periods=3 * 365, freq="D")
values = np.random.normal(loc=0, scale=1, size=len(dates)).cumsum()
df = pd.DataFrame(values, index=dates)

# Graph exportation 
fig = px.line(df, x=df.index, y= df.columns[0], )
fig = px.line(df, x=df.index, y=df.columns[0])
fig.write_image('graphique_test.png', width=800, height=500)  

Here is the graph :