Adding a background image to a slider Dash

Hi dear community people, I am a rookie on plotly/dash. For my work, I wish to add a background image, and use coding to describe some special features and points of the background. For example, I use the one on plotly website, I wish to add a background of the figure. Can someone help with this please?
Here is the code:

import plotly.express as px

img = io.imread(‘assets/example.png’)

df = px.data.gapminder()
px.scatter(df, x=“gdpPercap”, y=“lifeExp”, animation_frame=“year”, animation_group=“country”,
size=“pop”, color=“continent”, hover_name=“country”,
log_x=True, size_max=55, range_x=[100,100000], range_y=[25,90])

Thanks a lot