Prevent plpsql function to be invoked with rpc

I called

alter default privileges revoke execute on functions from public;

alter default privileges revoke execute on functions from public;

but my function is still available to be invoked with

supabase.rpc

supabase.rpc

. What can I do to prevent a function from being accessible by users?

Prevent plpsql function to be invoked with rpc - Supabase