Mutation in Apollo Client

I am using apollo client to perform an auto login with refresh token. The code I use is:

 const expirationTime = exp * 1000 - 60000;
if (Date.now() >= expirationTime) {
  await client //this is how user relogin
  .mutate({
    mutation: USER_LOGIN,
    variables: { rt: localStorage.getItem("refreshToken") },
  })
  .then((response) => console.log(response.data))
  .catch((err) => console.error(err));
}

But I am not sure whether this is the right way, because my app seems to crash when I do this. I read the documentation for react but couldn't find anything other than useMutation