As it suggest HERE you have to add a dependency in your build.gradle:
implementation 'com.google.android.material:material:1.0.0-beta01'
Or if you already use google support design library you must change your app theme to inherit from a Material Components theme
<style name="Theme.MyApp" parent="Theme.MaterialComponents.Light">
<!-- ... -->
If you cannot change your theme to inherit from a Material Components theme, you can inherit from a Material Components Bridge theme.
<style name="Theme.MyApp" parent="Theme.MaterialComponents.Light.Bridge">
<!-- ... -->
How Reyske said:
note that it is out of beta now! So you can use implementation 'com.google.android.material:material:1.0.0'