It's fake, but it's flux, unless you are in industry where you need to strictly control your process it will be just fine.
I've always found this chinese "amtech" stuff to be pretty good, but of course there's no assurance that one batch is the same as the next... but flux is not exactly rocket science.
I used to import, relabel so nobody would say "it's fake", and sell it locally in NZ no complaints ever, and of course used it myself. I stopped because I'm a goody-two-shoes and we had some hazardous substances law come in and I couldn't be bothered working out what might be required (not like I'd ever be able to get legit documentation for it anyway).