I need a Korean police clearance certificate for a job application in another country?

As a foreigner you get a Korean criminal record (police clearance) certificate from the police, and the process is similar to what citizens do. You can apply at a local police station's civil affairs desk or through the online Minwon24 / police portal, bringing your ARC and passport, and specify that it's for overseas use so it's issued in the right format. For use abroad you'll usually need it apostilled by the Ministry of Foreign Affairs afterward, and sometimes a certified translation. Processing is quick, often same day to a few days, and the fee is small.