And you have the 1800x current installed correct ???
And you also have a Video card, Correct ???
If so then you can update the BIOS using Instant Flash:
https://asrock.com/support/BIOSIG.asp?cat=BIOS10
BUT, I would strongly Recommend that you do Not use a BIOS newer than v1.50.
The BIOS versions newer than that have newer AGESA versions in them and do NOT work as well with 1000 and 2000 series CPU's.
And Make SURE you update the Chipset Drivers Before you update the BIOS as stated in the BIOS version 1.50 notes:
https://asrock.com/MB/AMD/B450M-HDV R4.0/index.asp#BIOS