What was the specific error that the user discovered in their code related to the header function?

The specific error the user discovered in their code related to the header function was that headers must be sent before any output is sent to the browser. This means that any HTML, whitespace, or even a single space before the opening <?php tag will cause the header function to fail. To solve this issue, ensure that no output is sent before calling the header function.

<?php
ob_start(); // Start output buffering

// Your code here

header("Location: https://www.example.com"); // Redirect using header

ob_end_flush(); // Flush the output buffer