Hmm the doc build test looks like it might point to a bug here?

import plotly.express as px

df = px.data.iris()
fig = px.scatter(df, x="sepal_length", y="sepal_width", facet_col="species")
# sources of images
sources = [
    "https://upload.wikimedia.org/wikipedia/commons/thumb/f/fe/Iris_setosa_var._setosa_%282595031014%29.jpg/360px-Iris_setosa_var._setosa_%282595031014%29.jpg",
    "https://upload.wikimedia.org/wikipedia/commons/thumb/3/38/Iris_versicolor_quebec_1.jpg/320px-Iris_versicolor_quebec_1.jpg",
    "https://upload.wikimedia.org/wikipedia/commons/thumb/f/f8/Iris_virginica_2.jpg/480px-Iris_virginica_2.jpg",
]
# add images
for col, src in enumerate(sources):
    fig.add_layout_image(
        row=1,
        col=col + 1,
        source=src,
        xref="x domain",
        yref="y domain",
        x=1,
        y=1,
        xanchor="right",
        yanchor="top",
        sizex=0.2,
        sizey=0.2,
    )

fig.show()

Gives the error:

ValueError:
    Invalid value of type 'builtins.str' received for the 'yref' property of layout.image
        Received value: 'y domain domain'

Also we should add a changelog entry for this fix 🎉

Yes, you are right! From the looks of it, I think there is a pretty straightforward fix, I'll try to verify and update later today. Thanks for taking a look at this!

The bug showing in the build-doc is fixed and I updated changelog! 👍

• I have added a CHANGELOG entry if fixing/changing/adding anything substantial.

I tried the bugfix, and while the hline is now working if set to yref=y3 for example, an annotation_text is not displayed at all!

Hey @endursa, can you post what you are working with? I tried to reproduce the error you mentioned but the following test I ran is working correctly:

import plotly.graph_objects as go

fig = go.Figure()
fig.add_traces(go.Scatter(x=[1,2,3],y=[1,2,3], yaxis='y',name='y1 trace'))
fig.add_traces(go.Scatter(x=[1,2,3],y=[3,2,1], yaxis='y2',name='y2 trace'))
fig.add_traces(go.Scatter(x=[2,3,4],y=[4,4,3], yaxis='y3',name='y3 trace'))

fig.add_hline(y=3, yref='y3', label={'text':'hline annotation text on y3'})
fig.add_hrect(y0=3.5, y1=4, annotation_text='hrect annotation text on y3', yref='y3')

fig.update_layout(
    xaxis=dict(domain=[0, 0.9]),
    yaxis=dict(title="yaxis1 title"),
    yaxis2=dict(title="yaxis2 title",overlaying="y",side="right",position=0.9,),
    yaxis3=dict(title="yaxis3 title",overlaying="y",side="right",position=1,)
)
fig.show()

This results in the following plot:

So maybe I'm misunderstanding what you mean by an annotation_text or it could be something else causing the bug. Can you please post a MWE or provide details on how you generate the non-displayed annotation-text? Is it a subplotted figure object or non-subplotted figure object? Is the annotation text supposed to be on an hline,hrect,layout_image,etc.? I'm happy to investigate but just can't seem to reproduce it.

yes of course, my problem looks like this:
import plotly
import plotly.graph_objects as go

fig = go.Figure()
fig.add_traces(go.Scatter(x=[1,2,3],y=[-0.009,-0.008,-0.01], yaxis='y',name='y1 trace'))
fig.add_traces(go.Scatter(x=[2,3,4],y=[-50,-52,-58], yaxis='y3',name='y3 trace'))

fig.add_hline(y=-58., 
              line_color='darkblue',
              yref = 'y3',
              line_dash='dot',
              annotation_text='annotation goes here (y3)',
              annotation_position='bottom right'
              )
fig.add_hline(y=-52., 
              line_color='darkblue',
              yref = 'y3',
              line_dash='dot',
              annotation_text='annotation goes here (y3)',
              annotation_position='bottom right'
              )    

fig.update_layout(
    xaxis=dict(
        title='some x axis',
        domain=[0.04,0.92],
        range=['2023-1-1','2024-1-1']),    
    yaxis=dict(
        title='some y axis',
        range=[-0.017,-0.0068],
        gridcolor='lightgrey'
    ),
    yaxis3=dict(
        title='another y axis',
        anchor='x',
        overlaying='y',
        side='right',
        tickmode='array',
        tickvals=[-52,-55,-58],
        range=[-60,-21],
    ),
)
plotly.offline.plot(fig,filename='plot_temp.html')

If one changes the yaxis range to

range=[-60,-0.0068]

the annotation and another hline appear

sideinfo:
I am running Python 3.10.9

Thanks for pointing this out and the code @endursa! Looks like I've got it figured out. It appears that when using the annotation_text parameter, the add_annotation function is called without passing the supplied yref see https://github.com/plotly/plotly.py/blob/fc3ef002c7a7898b9244b1549757a64e8df266dd/packages/python/plotly/plotly/basedatatypes.py#L4031-4037
So what is happening is the annotation is showing on the primary y and your shape is showing on the yaxis corresponding to the yref given. Interestingly, adding annotation text by passing text values in the label parameter such as:
label={'text':'my custom annotation'}
actually operates differently under the hood and therefore does not result in this bug. Regardless, I added the necessary yref kwarg to the offending function call and now it's working properly.

Thank you very much!
As far as my use case is concerned, it works now as expected :)

Hey @alexcjohnson anything else needed before merge?

Thanks for the nudge @zfoltz - I made a couple of minor changes, unfortunately I expect the tests will now fail not because of any issues here, but due to the same issue as in #4217 that I'm still trying to track down. Regardless, we'll get this into the next release.