powershell不能调用nuget.exe命令

Question

我有一个powershell脚本，可以检查nuget.exe是否存在，并且运行'nuget help'，

# Check if NuGet.exe is available.
if (-not (Get-Command "NuGet.exe" -ErrorAction SilentlyContinue)) 
{ 
    Write-Host "ERROR: NuGet.exe is not available. Install NuGet.exe and add to PATH or copy NuGet.exe into C:\Windows."
    exit
}
Write-Host "Confirmed NuGet.exe is in the path."

# run nuget command
$result = Invoke-Executable NuGet.exe "help"

Write-Host "result = $result"

如果我运行脚本，我在运行nuget.exe命令时会出现错误，即使找到了nuget.exe：

Confirmed NuGet.exe is in the path.
Invoke-Executable : The term 'Invoke-Executable' is not recognized as the name of a cmdlet, function, script file, or operable 
program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
At D:\repos\xdcr-nuget\packaging and publishing\auto.ps1:9 char:11
+ $result = Invoke-Executable NuGet.exe "help"
+           ~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (Invoke-Executable:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException
 
result =

在我的外面 ：脚本，仅从powershell命令行我可以运行nuget命令，例如nuget help完全可以。但是，如果没有此错误，PowerShell脚本无法运行任何Nuget命令，我在设置PowerShell脚本的方式上做错了什么？