Normaly you can look at award or ami www and with a 2 letters code from your bios serial number you can found manufacturer, and then on manufacturer www you can found your bios update.
Try https://www.wimsbios.com/ for help with it.
They are very good, I have always found success from there whenever I have wanted a new BIOS.
(Hint; write down your BIOS string 1st).