Open Whatsapp from React Native app with Expo

Currently trying to open whatsapp from my React Native app with Expo. I have the code below:

let url = 'whatsapp://app';
    Linking.openURL(url).then((data) => {
      console.log('WhatsApp Opened');
    }).catch((err) => {
      console.log(err);
      alert('Make sure Whatsapp installed on your device');
    });

The error I get is this:

Error: Could not open URL 'whatsapp://app': No Activity found to handle Intent { act=android.intent.action.VIEW dat=whatsapp://app flg=0x10000000 }

However when I change the url to send, it opens whatsapp fine?

whatsapp://send?phone=3464478983

I am trying to only open whatsapp without a send param