Create a spikes crosshair on simple line plot

📊 Plotly Python
1

How to add the horizontal white spikeline from hovermode='y unified' to the y axis tag from hovermode='y' (and remove the hovertemplate (inside the plot area) ? The result should have the gray label and a white solid line across the chart where the mouse (or otherwise a datapoint nearby is).

image

with hovermode='y' it is:
image


import numpy as np
import plotly.graph_objects as pl_go
import plotly.express as px

slug = np.random.random_sample((200,))

fig = pl_go.Figure()
fig.add_trace(  # DYNAMIC
    pl_go.Scatter(x=slug[:100],
                  y=slug[100:],
                  name='trace1_y1',
                  #                marker_line_width=0,
                  #                marker_color='green' # or array,
#                 hovertemplate=None,
                  )
)
# fig.update_traces(hovertemplate=None)
fig.update_layout(
    xaxis_zeroline=False, 
#     yaxis_zeroline=False,
    yaxis=dict(
        tickfont=dict(size=14, color='#e6e6e6'),
        #         title='Quote',
        #         titlefont_size=16,
        gridcolor='#283442',
        linecolor='#283442',
        spikecolor="white", spikethickness=1, spikedash='solid', spikemode='across',
    ),
#     hoverdistance=0,
    hovermode='y',
    font=dict(
        color='white',
        size=15
    ),
    paper_bgcolor='rgb(17,17,17)',
    plot_bgcolor='rgb(17,17,17)',
)
fig.show()

related: forum found without solution: Spikes or crosshair on 2D plots
https://stackoverflow.com/questions/61794582/plotly-how-to-only-show-vertical-and-horizontal-line-crosshair-as-hoverinfo

EDIT: is there a simple solution to get a crosshair under the cursor with x,y coordinates displayed near the tickerlabels, no local hover box? so much doc* but no simple crosshair

2

to make it simple, maybe i overlooked sth in the docs: how to make a white crosshair under the cursor with labels (second picture left gray label) showing on both axis of the 2d scatter plot?