Nothing bad will happen if you ignore this. You’ll just keep getting the message on boot.

If you want to fix it, you’ll need to upgrade your BIOS. Find out what motherboard you have and go to the manufacturer’s website; then download the latest BIOS. Put that file on a FAT formatted thumb drive and boot to your BIOS (hold either F2 or DEL on boot, look up the key for your motherboard manufacturer). In the BIOS there will be a option to upgrade the BIOS from USB. Run that and you should be good to go!

Memorial for Charlie Kirk. 63,000 people: https://www.cbsnews.com/live-updates/charlie-kirk-memorial-service/