Hello! I'm here to help with your question. It's possible that the Philippines may not be listed as an option for registration on Chegg Skills due to various reasons such as regional availability, legal restrictions, or other factors specific to Chegg's platform. I recommend reaching out directly to Chegg's customer support for more information on why the Philippines may not be included as an option for registration. They will be able to provide you with the most accurate and up-to-date information regarding this matter.