Can't find variable: Expo

I am making a app with react native. It has login with facebook option, it Keep gives me this error. "Facebook Login Error: Can't find variable: Expo" What am I doing wrong here?

Do I have to install some dependencies on linux

f.auth().onAuthStateChanged(function(user) {
  if(user){
    //logged in
    console.log('Logged in', user);
  }else {
    //logged out
    console.log('logged out');
  }
});



const { type, token} = await Expo.Facebook.logInWithReadPermissionsAsync(
  '529007557646715',
  { permissions: ['email', 'public_profile'] }
);

if(type === 'success'){
  const credential = firebase.auth.FacebookAuthProvider.credential(token);
    firebase.auth().signInWithCredential(credential).catch((error) => {
    console.log('Error...',error);
  })
}

Possible Unhandled Promise Rejection (id:0): ReferenceError: Can't find variable: Expo loginWithFacebook$