1. Go to this page and download the library: Download bnomei/kirby3-posthog library. Choose the download type require.
2. Extract the ZIP file and open the index.php.
3. Add this code to the index.php.
<?php
require_once('vendor/autoload.php');
/* Start to develop here. Best regards https://php-download.com/ */
// track page view event for current kirby user or identified posthog user
$page->posthogCapturePageView();
// be careful to not have any whitespace before <html>
><html>
<!-- ... --->
</html>