Get access token from AAD for app with ClientId and ClientSecret in PowerShell to be used in HTTP request

Get-CorpGraphAccessToken.ps1

function Get-CorpMicrosoftGraphAccessToken
{
    Param(
        [Parameter(Mandatory=$true)]
        [string]$TenantId,
        [Parameter(Mandatory=$true)]
        [string]$ClientId,
        [Parameter(Mandatory=$true)]
        [string]$ClientSecret
    )

    $Body = @{
        tenant = $TenantId
        client_id = $ClientId
        client_secret = $ClientSecret
        scope = "https://graph.microsoft.com/.default"
        grant_type = "client_credentials"
    }

    $Response = Invoke-RestMethod -Uri "https://login.microsoftonline.com/$TenantId/oauth2/v2.0/token" -Body $Body -Method Post -ContentType "application/x-www-form-urlencoded"

    return $Response.access_token
}