PHP Script for Popup Banner Integration

I am seeking a talented developer to create a robust PHP script integration for uploading and displaying popup banners across various websites. The banners will be in HTML format and need to be centered on the screen without being attached to the main site content.

Key Requirements:
- Develop a universal integration method for the PHP script.
- The script should be loadable via `require __DIR__`, `index.php`, and `function.php`.
- Ensure the banner remains centered on the screen.
- The development time for this task is 1-3 hours after the order is accepted, with potential for negotiation on additional time.

Ideal Skills and Experience:
- Strong proficiency in PHP and web development.
- Experience with integrating scripts into diverse website architectures.
- Ability to work efficiently under tight deadlines.
- Problem-solving skills to ensure seamless banner display.

This project may lead to further web development tasks. If you have the skills and are ready to take on this challenge, I look forward to your bid.