# Page Not Found

The URL `legacy-api-plans/api-response-mode-legacy/api-mode-for-authentication` does not exist.

You might be looking for one of these pages:
- [PICCData / Meta Authentication](https://docs.ixkio.com/flex-api/flex-api-getting-started/piccdata-meta-authentication.md)
- [Flex API NTAG424 Authentication](https://docs.ixkio.com/flex-api/flex-api-getting-started/flex-api-ntag424-authentication.md)
- [CodeLink Integration](https://docs.ixkio.com/advanced-features/codelink/codelink-integration.md)
- [Using the Flex API](https://docs.ixkio.com/flex-api/flex-api-getting-started/using-the-flex-api.md)
- [Response Modes Explained](https://docs.ixkio.com/response-modes/response-modes-explained.md)

## How to find the correct page

1. **Browse the full index**: [/sitemap.md](https://docs.ixkio.com/sitemap.md) - Complete documentation index
2. **View the full content**: [/llms-full.txt](https://docs.ixkio.com/llms-full.txt) - Full content export

## Tips for requesting documentation

- For markdown responses, append `.md` to URLs (e.g., `/flex-api/flex-api-getting-started/piccdata-meta-authentication.md`)
- Use `Accept: text/markdown` header for content negotiation