import { ActivityIndicator } from 'react-native'
import { Button, Overlay, Text } from 'react-native-magnus'

const [overlayVisible, setOverlayVisible] = useState(false);

<Button
  onPress={() => {
    setOverlayVisible(true);

    setTimeout(() => {
      setOverlayVisible(false);
    }, 2000);
  }}
  block>
  Show Overlay
</Button>

<Overlay visible={overlayVisible} p="xl">
  <ActivityIndicator />
  <Text mt="md">Loading...</Text>
</Overlay>