Generate Simple Sitemap using PHP

.htaccess (File)

RewriteRule ^sitemap.xml$ sitemap.php [L]

sitemap.php (File)

<?php 
//sitemap.php
$connect = mysqli_connect("localhost", "user", "password", "database");
$query = "SELECT username FROM table_name";
$result = mysqli_query($connect, $query);
$base_url = "https://domain.com/";
header("Content-Type: application/xml; charset=utf-8");
echo '<?xml version="1.0" encoding="UTF-8"?>'.PHP_EOL; 
echo '<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9 http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd">' . PHP_EOL;
while($row = mysqli_fetch_array($result))
{
 echo '<url>' . PHP_EOL;
 echo '<loc>'.$base_url.'/</loc>' . PHP_EOL;
 echo '<changefreq>daily</changefreq>' . PHP_EOL;
 echo '</url>' . PHP_EOL;
}
echo '</urlset>' . PHP_EOL;
?>