UPDATE

jupyter_lab_config.py

@@ -12,3 +12,6 @@ c.NotebookApp.trust_xheaders = True
 c.NotebookApp.allow_origin_pat = ".*"
 c.NotebookApp.allow_credentials = True
 c.NotebookApp.disable_check_xsrf=True
+c.LabApp.collaborative = True
+c.LabApp.app_settings_overrides = {
+}
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