RAG Web App with OpenAI Integration

I need a Retrieval-Augmented Generation (RAG) web application that features a ChatGPT-like user interface. The app should allow for future uploads of knowledge base documents (PDFs, Word docs, text files, audio, and video) and utilize OpenAI models to generate answers solely from this knowledge base.

Requirements:
- User access management via phone number and email
- Admin control over daily response limits per user
- Single repository for knowledge base documents
- Future-proof document upload capability

Ideal Skills:
- Experience with OpenAI API
- Proficient in web app development
- Familiarity with Google Firebase for hosting
- Strong background in user authentication and access management