Anonymous Sign In With Supabase

I've looked at the wrapper function for supabase in the backend/supabase.dart and wrote this as my custom action

void anonSignIn() async {
  await SupaFlow.initialize();
  final supabase = SupaFlow.client;
  await supabase.auth.signInAnonymously();
}

But it says that the method doesn't exist. I've confirmed that supabase.auth is returning a GoTrueClient and the docs say that GoTrueClient has the method. So how do I login anonymously??? I can't do it in a new edge function because the edge function in supabase would require a JWT which is what I'm trying to get by anon sign in.