Cannot install windows 11 using Bootcamp

Mac mini (2018) 

12.1 

Download and install Windows support software on your Mac 

-macOS 12.1 installed 

-Format Flash drive to masterboot record, ms dos fat 32 

-Plug the USB on the mac 

-Open bootcamp but it says we need to unplug the USB 

-unplug usb

-Choose the ISO 

-Install it and then error comes up after it shows downloading: Can’t install the software because it is not currently available from the software update server 

-click windows in menu bar > download the windows software but same error appears 

Is Windows 11 compatible with bootcamp? 

Can I downgrade the mac mini OS and see if we can install windows 11?