Expo - Firebase Email Verification

Im try to send a verification email to the user when he creates his account. Currently it works when Im running it on the expo app in development mode, but when I build the app there is no email sent from firebase

This is the code which sends the verification.

const user = firebase.auth().currentUser
user.sendEmailVerification().then(() => {
     navigation.navigate("Main")
}).catch((err) => {
     console.log(err)
})

Im using managed workflow SDK 41