Ok I understand… 
EDIT: Is the TUF B450M-PLUS GAMING BIOS not compatible with UBU ([Tool Guide+News] "UEFI BIOS Updater" (UBU))?
In the simplest case, the microcode from the AMD Ryzen 5 5600 can then be integrated into the BIOS 1804. And by the way, you could then renew all the other upgradeable components.