On a first sight it looks legit. I can’t find a website, but there is a “Prochem Pharmacy Avondale” facebook page. Since january 2022 it advertises products sold there, give aways and such. It could be that it does that longer and facebook just doesn’t show me all as a visitor without an account, not sure. The profile picture literally says “Free Palestine - End the occupation”.

It is indeed possible that that’s a big false flag effort, but so far I have no reason to belief that.