error using Get-GPRegistryValue

I am running a command as below:

Get-GPRegistryValue -Name "test" -key "HKEY_LOCAL_MACHINE"

However I am getting the error:

Get-GPRegistryValue : The argument value cannot be an empty string.
Parameter name: keyPath
At line:1 char:1
+ Get-GPRegistryValue -Name "test" -key "HKEY_LOCAL_MACHINE"
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidArgument: (Microsoft.Group...tryValueCommand:GetGPRegistryValueCommand) [Get-GPRegistryValue], ArgumentException
    + FullyQualifiedErrorId : UnableToRetrievePolicyRegistryItem,Microsoft.GroupPolicy.Commands.GetGPRegistryValueCommand

The test GPO has SMB Signing related group policy settings defined. However I get this error message and even I give the full

registry path as HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters, I still get an error.

What am I doing wrong here.