I have some interest for this example : https://esri.github.io/esri-leaflet/examples/premium-content.html
(I want to add a private layer in my Esri-Leaflet project with an authentification.)
The exemple work fine on the Esri-Leaflet Web site. But When I try it on my own (in a doc.html on my computer), it doesn't work. when I click on the link "Add trafic layer", it says" 'Invalid redirect_uri - error 400".
Does someone know why ?