Send a POST reguest to Microsoft Graph from PowerShell

Send-CorpGraphPostRequest.ps1

function Send-CorpMicrosoftGraphPostRequest
{
    Param(
        [Parameter(Mandatory=$true)]
        [string]$Domain,
        [Parameter(Mandatory=$true)]
        [string]$AppId,
        [Parameter(Mandatory=$true)]
        [string]$AppSecret,
        [Parameter(Mandatory=$true)]
        [string]$RequestUrl,
        [Parameter(Mandatory=$false)]
        [string]$RequestBody
    )

    $Result = $null

    try 
    {
        # Connect to Microsoft Graph to aqure a valid token
        $Token = Get-CorpMicrosoftGraphAccessToken -TenantId $Domain -ClientId $AppId -ClientSecret $AppSecret

        #  Request
        $Headers = @{"Content-Type" = "application/json" ; "Authorization" = "Bearer " + $Token}

        # Send request
        if ($RequestBody -eq $null)
        {
            $Result = Invoke-RestMethod -Method Post -Uri $RequestUrl -Headers $Headers
        }
        else
        {
            $Result = Invoke-RestMethod -Method Post -Uri $RequestUrl -Headers $Headers -Body $RequestBody
        }
    }
    catch
    {
        $Result = $_.Exception.Response.StatusCode.value__
    }

    return $Result
}