与此SO讨论相关的潜在重复用例......
PowerShell: retrieve file from GitHub

$url = 'https://github.com/mycompany/myrepo/blob/master/myscript.ps1'
$wc  = New-Object -TypeName System.Net.WebClient
$wc.Headers.Add('Authorization','token your_token')
iex ($wc.DownloadString($url))

..当然没有调用WebRequest。
另见：
Using PowerShell and oAuth

# Modified article code
Invoke-RestMethod https://api.github.com/repos/MyAccount/MyRepo/contents/MyFile.txt -Method Get -Headers @{"Authorization" = "Bearer $accessToken"}

我不得不在Powershell中更改脚本才能让它工作：

$credentials="<github_access_token>"
$repo = "<user_or_org>/<repo_name>"
$file = "<name_of_asset_file>"
$headers = New-Object "System.Collections.Generic.Dictionary[[String],[String]]"
$headers.Add("Authorization", "token $credentials")
$headers.Add("Accept", "application/json")
$download = "https://raw.githubusercontent.com/$repo/main/$file"
Write-Host Dowloading latest release
Invoke-WebRequest -Uri $download -Headers $headers -OutFile $file