Push notification icon (no replies)

Hi all,

how can i show a custom image inside a push notification on Android/ios?
Until now i've tried with ios following the instructions and the examples of the product but without success. Even if i bundle the image in a relative path (eg. images/notification/notif.png) and send this string inside the ..Icon attribute of the notification, the image doesn't shows up.. what i'm doing wrong? the image is multi-dpi.. but this maybe is not a problem isn't it?