Merge pull request #6862 from dsblank/patch-3

Update the version of jupyterlab manually

docs/source/developer/extension_tutorial.rst

@@ -76,6 +76,13 @@ Note: You'll need to run the command above in each new terminal you open
 before you can work with the tools you installed in the
 ``jupyterlab-ext`` environment.
 
+Note: if you have an older version of JupyterLab previously installed, you may need to update
+the version of JupyterLab manually.
+
+.. code:: bash
+
+    conda install -c conda-forge jupyterlab=1
+
 Create a repository
 ~~~~~~~~~~~~~~~~~~~