Integrate Invoice VAT Fiscalization API into SaaS

I'm seeking an expert to integrate a third-party API into my SaaS website, which is built using the Codeigniter software framework. The primary goal is to enable the fiscalization of invoices through this integration. The API comes with detailed technical documentation, which should facilitate a smooth integration process.

Key Requirements:
- Integrate the third-party API for fiscalization of invoices.
- Ensure seamless interaction between the API and the invoice generation module.
- Maintain the integrity and functionality of the existing system.

Ideal Skills and Experience:
- Strong proficiency in Codeigniter, JavaScript, JSON, HTML, CSS, PHP, and SQL.
- Experience with API integration, particularly in financial or invoicing contexts.
- Ability to understand and implement detailed technical documentation.
- Excellent problem-solving skills and attention to detail.

If you have the expertise to enhance my SaaS with this API integration, I look forward to your proposals.