The webmap does not allow adding markers by clicking on it. Although, you can use the geoaxes plot to add markers to the webmap. The function ginput is used to retrieve the latitude and longitude in a vector by clicking click on the geoaxes plot. This vector can be used to add markers on the webmap by using the wmmarker function. The following code demonstrates for adding three markers on the webmap by clicking on the geoaxes plot:
webmap;
geoaxes('Basemap','streets');
[lat,lon] = ginput(3);
wmmarker(lat,lon);
Hope this helps!
