Flash player

I'm on my computer and I'm trying to play a game that's online and suddenly this button pops up that says "get adobe flash player" and next to it there is an arrow pointing down and once I click it it says Allow flash player sometimes though,it would do nothing at all. and every once in a while when I go to a site that worked before with adobe flash It no longer works until 2-3 days after. I've tried many things including Clicking The secure connection button but all I get is "allowed by your administrator  because I'm on my mom's boyfriend's computer And it has more than one account. Also,I am On chrome os chromebook and i've been hearing that chrome os isn't compatible with Chrome os so i've been wondering is there any way to work it on chrome os if that is true? if so please Reply to this if it's neither of those Please give me some recommendations.