How to display map object using ipyleaflet in jupyter notebook or jupyter Lab

I am trying to run jupyter notebook and/or jupyter Lab on mac book Catalina.

Code

from ipyleaflet import Map, Marker

start_location = (53.551086, 9.993682)

m = Map(center=start_location, zoom=16, scroll_wheel_zoom=True)

display(m)

I get no error message pops up in notebook. The map object does not display but gets created. type(m) outputs ipyleaflet.leaflet.Map

In jupyter Lab I get this error message : Error displaying widget: model not found

I have followed these suggestions : https://gis.stackexchange.com/questions/303261/ipyleaflet-map-object-doesnt-display-in-jupyter-notebook-but-it-gets-created and https://github.com/jupyter-widgets/ipyleaflet/issues/504 but the same error remains.

Could someone help me with this issue ?