Hi Alex
Welcome to the community!
For any of the AMT scripts, you can always get the help info by typing:
get-help modulename-full
Example:
get-help get-amtfirmwareversion -full
If you typed the command as you are showing it:
Get-AMTFirmwareVersion -ComputerName:<ComputerName>
the result is correct, unless the computer name of the system you are running it on IS ComputerName, then replace with the name of the system and remove the <>, so example:
Get-AMTFirmwareVersion -Computername: michaelspc
Regards,
Michael