React Native Blank MapView

I am starting to "learn" React Native and the first tutorial I see uses a <MapView /> component. I have tried different ways to show a map but I am not able to.

According to the video itself, it imports MapView from expo. But after reading some documentation at the Expo site I changed the import to react-native-maps. The error changes but there is no map at all.

When importing MapView from expo I get an Invariant Violation error. But when importing it from react-native-maps I get a blank screen on Android and iOS simulators.

I found this online real-time editor with their own iOS / Android / Web simulators. This is the example: https://snack.expo.io/B1H3VWtDH

This is the code. It has two lines...

import React from 'react';import { Text, View } from 'react-native';import MapView from 'react-native-maps';function App() {  const [region, setRegion] = React.useState({    latitude: -30.8501718,    longitude: -50.1700368,    latitudeDelta: 0.922,    longitudeDelta: 0.0421  })  return (<View><Text>Map screen</Text><MapView        initialRegion={region}        style={{ flex: 1 }}      /></View>  );}export default App;

What is wrong? Any comments will be appreciated.