problem image notification

[Yboss2]

Hey guys thank you for this great app!
im using the last version on android. build 762.

i follow the 3 steps to receive image notification but didn'work for me. i register the app,... I received well the notification popup but without image. The picture is well generated in my folder config/www.

i tried also to call the service like this :

i received only the notification without pic.
title: hello
message: world
data:
image : /config/www/ab.jpg

this working fine : i received the pic with notification
title: hello
message: world
data:
image : https://upload.wikimedia.org/wikipedia/en/9/95/Test_image.jpg

I cheked in my folder www and the pic file "ab" exists so i dont underdstand whats happen. Anyone could help ? thanks