How to redirect if the param is not present Next.JS

I have page which can have one of 2 params. email and hash if there are not present I want to redirect the user.

/confirm-email?email=user@email.com

I have tried the following:

const router = useRouter();
const { email, hash } = router.query;

useEffect(() => {
  if (!email && !hash) {
    router.push('/');
  } else if (hash) {
    // Do stuff
  }
}, [email, hash, router]);

But the problem on first render both of them are undefined and the user gets redirected even if the hash or email params are present.

How can I fix this ? any suggestions ?

After doing some research. I have figured out it's best check if the params exists or not inside getServerSideProps()

export async function getServerSideProps({ query }) {
  if (!query.email && !query.hash) {
    return {
      notFound: true,
    };
  }

  return {
    props: {},
  };
}