Firebase登录并重定向

Question

我正在使用Firebase和Redirect登录。在这里，第4行的代码不起作用，我在哪里弄错了？

export const startLogIn = () =>{
return () => {
    firebase.auth().signInWithRedirect(googleAuthProvider);
    return firebase.auth().getRedirectResult()
            .then(result => {
                console.log(result);
                const profile = result.user;
                const user = {
                    uid : profile.uid,
                    name : profile.displayName,
                    avatar : profile.photoURL
                }
                if(result.additionalUserInfo.isNewUser){
                    axios.post(`http://localhost:5000/api/user`, user)
                        .then(res => {
                            console.log(res.data);

                        });
                }
            });
 };
 };