Double X-axis bar chart

[njohnson]

Hello,

I would like to have two x-axis titles to my barchart.
I was able to add them but my second x-axis title isnt appearing.

import plotly.graph_objects as go
import string

unstacked = go.Bar(
    y=[37, 25, 21, 17, 14],
    base=0,
    width=0.45,
    offset=0,
    textposition='auto',
    texttemplate='%{y}'
)

stackedbottom = go.Bar(
    y=[24, 10, 9, 11],
    base=0,
    width=0.45,
    offset=0.45,
    textposition='auto',
    texttemplate='%{y}'
)

stackedtop = go.Bar(
    y=[13, 15, 12, 0, 8],
    width=0.45,
    offset=0.45,
    base=[24, 10, 9, 0, 0],
    textposition='auto',
    texttemplate='%{y}'
)

fig = go.Figure(data=[unstacked, stackedbottom, stackedtop])

letters = list(string.ascii_uppercase[:5])
ticktext = []
tickvals = []
width = 0.45

for k in range(0, 5):
    tickvals.extend([0.5 * width + k, 1.5 * width + k])

for letter in letters:
    ticktext.extend([f'{letter}1', f'{letter}2'])

fig.update_layout(xaxis_tickvals=tickvals,
                  xaxis_ticktext=ticktext,
                  xaxis_range=[-0.2, 5],
                  annotations=[dict(x=X, y=Y, text=t, xref='x', yref='paper',
                                     showarrow=False) for X, Y, t in zip([0.45, 1.45, 2.45, 3.45, 4.45], [1.07]*5, [201, 202, 203, 204, 205])])

for k in range(4):
    fig.add_vline(x=k + 0.95)

# Adding layout to the figure
fig.update_layout(
    title="Double X Axis Example",
    xaxis=dict(title="Categories"),
    xaxis2=dict(title="Rooms", overlaying='x', side='top'),
    yaxis=dict(title="Y values")
)

fig.show()