I m getting strange issue, whenever i run debug build in my phone having android version 9 then i got the notification icon. But in release build showing empty icon. I tried changing icon as well but still showing empty icon.
You can check in screenshot below. (app name -> Vehicle 24x7)

See the note in the readme on resource shrinking. You'll need to do some configuration on the Android side to avoid this from happening and there's an XML file for the example app that can be used as reference.
This is the link to the XML file that is applicable to the example app in the repo https://github.com/MaikuB/flutter_local_notifications/blob/master/flutter_local_notifications/example/android/app/src/main/res/raw/keep.xml
let me try
yes problem resolved,
thanks.
Most helpful comment
See the note in the readme on resource shrinking. You'll need to do some configuration on the Android side to avoid this from happening and there's an XML file for the example app that can be used as reference.