To enable all error debugging in PHP, you can use the following PHP code snippet. This will display all errors, warnings, and notices:
<?php
// Turn on all error reporting
error_reporting(E_ALL);
// Display errors
ini_set('display_errors', 1);
// Optionally, you can log errors instead of displaying them
// ini_set('log_errors', 1);
// ini_set('error_log', '/path/to/php-error.log');
echo "Error reporting is enabled.";
?>