bios upgrade update i5-9600

Hi guys. I recently bought a Asrock H370M PRO4 with a I5-9600K cpu. I know right. K cpu with a H mainboard. What he was thinking :). Don't o/c! The thing is the mainboard BIOS need to be updated to the lastest version 3.20 for it to run this cpu. As I don't have any first 8th generation cpu...