How to get the name/ID of the current map layer in Leaflet?

Question

JavaScript

How to get the name/ID of the current layer in Leaflet?
Tried like this, but the IDs are dynamic:

map.on('baselayerchange', function(e){
alert(e.layer._leaflet_id);
});

The task is to somehow identify and save the layer in the cookie.

Answer 1

How to, how to read documentation
https://leafletjs.com/reference-1.6.0.html#layersc...