$headers = @{
    'Authorization' = "Bearer $accesstoken"
    'Content-Type'  = 'application/json'
}
$requesturi = "https://graph.microsoft.com/v1.0/users" 
$ret = (Invoke-RestMethod -Uri $requesturi -Headers $headers -Method Get)
$ret.Value |Select DisplayName,Mail, UserPrincipalName
$ret |ConvertTo-Json