Supabase Signup Authentication Implementation

I need an experienced developer to implement a signup authentication system using Supabase. The system should support signups with both email and phone number. It should also prevent duplicate signups with the same email or phone number by blocking the signup process for these users.

Key Requirements:
- Implement a signup system using Supabase
- Support for both email and phone number signups
- Prevention of duplicate signups with the same email or phone number
- Blocking of signup for users with a duplicate email or phone number

Ideal Skills:
- Proficient in Supabase
- Experience with user authentication systems
- Good understanding of preventing duplicate signups
- Ability to implement blocking of signups based on certain criteria.