
WordPress 503 Service Unavailable – The 503 service unavailable error occurs when your PHP version is not compatible with your WordPress website, either the WordPress theme or a plugin is not compatible with your PHP version.
How to FIX WordPress 503 Service Unavailable
- Login into your cPanel account and search for MultiPHP Manager

2. Mark your website that you wish to change the PHP and set it to PHP EA-7.3 or PHP EA-7.2

3. Check your website