Using defferent region game

Hi, I have a question about using games with different region. I live in Europe, but game I want to play is US region, since i cant get this game in my region. I have read in rpcs3 quickstart that i have to use correct region ID, but i am not sure, what it means. I know my game ID, but its not EUR region. It is a problem?

It doesn't really matter what region the game is from, whatever is the Game ID that the game comes with is the one you use. It's on the game box / game disc if it's a physical game, and it's on the name of the package / game folder if you buy it digitally.