Philippines is specifically listed on the country allowed to play on this casino so maybe they are licensed by PAGCOR. I tried to browse the PAGCOR website for the list of regulated casino but their website is so crappy that makes it hard to browse.
Here’s the list of Gamba allowed country:
Canada, Japan, South Korea, Brazil, Argentina, Chile, Mexico, South Africa, New Zealand, Malaysia, Philippines, Vietnam, Colombia, and many others.
List of allowed countries that ends with many others is very confusing. Nobody knows which countries are allowed in "many others" so it's better if there is a shorter but more clearer list of restricted countries.
It's easier to check that restricted countries list, then if you don't find your nation there, you can know that you as a citizen in that nation is allowed to join the casino. There is no confuse with this list that is contrasting with a list in your post contains "many others" at the end.