Layer property type

Hi,
I have this error using leaflet draw on ionic application :
Property ‘layer’ does not exist on type ‘LeafletEvent’.

this is the code :
this.map.on(‘draw:created’, function(e) {
var layer = e.layer;
drawnItems.addLayer(layer);
});

Please any solution ?
Thanks

var layer = e.layer;

So please how will i get drawn layer then ?