Simple Modern Website with ChatGPT Integration

I'm looking to build a simple, modern and minimalistic website with the following features:

- **User Authentication**: A secure Login/SignUp page.
- **User Input**: An entry form to collect text from users.
- **ChatGPT API Integration**: Utilizing the ChatGPT API to process user input and map responses to a PDF template for download.
- **Subscription Model**: Implementing a subscription model for users.
- **Admin Panel**: A comprehensive admin panel to manage user subscriptions and data.

The ideal freelancer for this project should have:
- Extensive experience in Flutter
- Proven track record of integrating APIs, particularly ChatGPT
- Skill in creating modern, minimalistic designs
- Experience in setting up subscription models and creating admin panels.