Integrate Upgraded PHP Tool

I have just finished upgrading a standalone PHP tool that handles data management and user authentication, and now I want it running smoothly inside my existing website. The code itself is production-ready, so I’m not looking for feature tweaks or redesigns—just a clean, error-free integration... (Budget: $3 - $10 NZD, Jobs: cPanel, Database Administration, HTML, LAMP, MySQL, PHP, Web Development, Website Design)