Manifest merger failed : Attribute application@theme value=(@style/AppTheme) from AndroidManifest.xml
follow the instructions that were given to you in the error message:
Suggestion: add 'tools:replace="android:theme"' to element at
AndroidManifest.xml:5:5-23:19 to override.
In other words, add tools:replace="android:theme" to your <application> element.
Or, switch to a different library.