Plug.upload doesn't seem to pick up uploaded file from app but works from web interface

Questions / Help
1

hey there,
if i use the web interface - file picker etc it is working nicely, but when I am trying to send the image from a react-native app it just returns the struct as the object i sent, plug.upload doesn’t touch it.
why is that?

website version user_params logged:

%{
  "avatar" => %Plug.Upload{
    content_type: "image/jpeg",
    filename: "ConceptArt_SneakySneaky_011 (2).jpg",
    path: "/tmp/plug-1536/multipart-1536643366-594696545916483-1"
  }
}

app version user_params

%{
  "avatar" => %{
    "name" => "testpic",
    "type" => "image/jpeg",
    "uri" => "file:///storage/emulated/0/DCIM/IMMQY/IMG_20180911121208_999.jpg"
  }
}

this is if i send the whole image that is returned in the app:

%{
  "avatar" => %{
    "height" => 960,
    "mime" => "image/jpeg",
    "path" => "file:///storage/emulated/0/DCIM/IMMQY/IMG_20180911122943_849.jpg",
    "size" => 117832,
    "width" => 960
  }
}