How to set shadows via xml under android 4?

Question

Android

I'm racking my brains on what attribute to set the shadow under the cards. I'm trying android:elevation, but it works on the Android 5 API. However, there are a bunch of applications on the 4th droid with shadows. How does everyone do it?
I would be grateful for a clear explanation and links to examples :)

Answer 1

on the 4th under the cards it also works, only in the root element add xmlns:app=" schemas.android.com/apk/res-auto " and where you need to use elevation:
app:elevation="4dp"