here is my code:

const [user] = useAuthState(auth);

function submitPostHandler() {
    if (user) {
        const currentUser = auth.currentUser;
        firestore.collection("posts").add({
            title: title,
            desc: desc,
            imgUrl: imgUrl,
            poster: currentUser.displayName,
            createdAt: new Date().toISOString(),
            comments: []
        });
        console.log(currentUser);
        //navigate("/all-posts");
    }
    else {
        navigate("/login");
    }
}

Simple, whenever I run this function it logs an object that has properties that are undefined as in if I switch console.log(currentUser); with console.log(currentUser.displayName) it logs undefined. Unusually useAuthState(); returns true.

It seems like when I was creating the user with the createUserWithEmailAndPassowrdOrSomething() I was not passing in the email and password. I forgot to change this when @Dharmaraj told me before.