How to locate an annotation below a line?

When I do annotation, its positions is alway on top-left (please see the below code). How can I do it on “bottom-center”?

I tried with ‘align’ and ‘xanchor’, etc., but none solves my problem.

import plotly.graph_objs as go
import as pio
pio.renderers.default = 'chrome'

x = list(range(1, 10))
y = list(range(21, 30))

fig = go.Figure()
fig.add_trace(go.Scatter(x=x, y=y))

fig.add_annotation(x=x[4], y=y[4], arrowsize=2, text='here')

Thank you for any comment in advance :slight_smile: