$cache_url = '?08062021';
echo '<img src="img.png'.$cache_url.'">';
$cache_url = '?' . time();
echo '<img src="img.png' . $cache_url.'">';<?php
ob_clean();
ob_start();
header("Cache-Control: no-store, no-cache, must-revalidate, max-age=0");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");
?>