What could be causing the "503 Service Unavailable" error when using a specific code snippet in PHP?

The "503 Service Unavailable" error typically occurs when the server is temporarily unable to handle the request. This can happen due to server overload, maintenance, or misconfiguration. To solve this issue, you can try increasing server resources, checking server logs for any errors, or optimizing your code to reduce server load.

// Example code snippet to handle the "503 Service Unavailable" error
header("HTTP/1.1 503 Service Unavailable");
echo "503 Service Unavailable - Please try again later";
exit;