plot.ly offline mode in jupyter lab not displaying plots

A couple things might be happening. For some reason is your Notebook "Not Trusted?" This will stop the Plotly javascript from rendering anything below.

Another possibility is that you don't have the Plotly extension installed for Jupyter Lab. In Lab, as compared to Notebooks, there are a lot more restrictions on what javascript can execute, so packages need to have extensions installed in order to display anything beneath the cell.

Look for the plotly-extension with jupyter labextension list

and install it if missing with: jupyter labextension install jupyterlab-plotly

Plotly-extension has been deprecated, use another:

jupyter labextension install jupyterlab-plotly

it worked for me and it has no compatibility issues with the latest versions of plotly (currently 4.9.0) / jupyterlab

source: https://plotly.com/python/getting-started/ , https://www.npmjs.com/package/@jupyterlab/plotly-extension

Try changing the renderer:

import plotly.io as pio
pio.renderers.default = 'iframe' # or 'notebook' or 'colab' or 'jupyterlab'

You can loop through the list like this to see what fits you

import pandas as pd
import plotly.express as px
import plotly.io as pio

for text in pio.renderers:
    print(text)
    pio.renderers.default = text

    df = px.data.iris()
    fig = px.scatter(df, x="sepal_width", y="sepal_length", color="species")
    fig.show()

One way to do it will be using HTML to help JupyterLab show figures. One example will be:

import plotly.express as px
from IPython.display import HTML

df = px.data.tips()
fig = px.scatter(df, x='total_bill', y='tip', opacity=0.65,
                 trendline='ols', trendline_color_override='darkblue')
HTML(fig.to_html())