...
const { cookies, redirect } = Astro;

const accessToken = cookies.get("sb-access-token");
const refreshToken = cookies.get("sb-refresh-token");

if (!accessToken || !refreshToken) {
  return redirect("/signin");
}
let setSession: AuthResponse;
try {
  setSession = await supabase.auth.setSession({
    refresh_token: refreshToken.value,
    access_token: accessToken.value,
  });
  if (setSession.error) {
    cookies.delete("sb-access-token", {
      path: "/",
    });
    cookies.delete("sb-refresh-token", {
      path: "/",
    });
    return redirect("/signin");
  }
} catch (error) {
  return redirect("/signin");
}
const email = setSession.data.user?.email;
...