Ionic Push not working, build failed

It seems the dex version is causing the error.
You can build but by removing the platforms and plugin folder from your app. I know that’s not a solution but you can do that for checking purpose.
I think the some plugin is creating some issue.
Back up your project in another folder then try deleting the platform folder and plugin folder after that re-add the platforms then you can build.
You can follow this:
(com.android.builder.dexing.DexArchiveMergerException: Unable to merge dex)