Fedex-How to define SpecialServicesRequested SignatureOption for php-fedex-api-wrapper

Question

I'm struggling to create a shipService Request with Signature option.
No matter what i send I always receive [SignatureOption] => SERVICE_DEFAULT, but I need to send with [SignatureOption] => DIRECT
I contacted the Fedex about this problem and they told me that U need to use SpecialServiceTypes for SignatureOption

I tried with this code

$packageLineItem1->setSequenceNumber( 1 )
        ->setItemDescription( 'Product TEST' )
        ->setSpecialServicesRequested( new ComplexType\PackageSpecialServicesRequested( [
        'SpecialServiceTypes'   => SimpleType\PackageSpecialServiceType::_SIGNATURE_OPTION,
        'SignatureOptionDetail' => new ComplexType\SignatureOptionDetail( [
        'OptionType' => SimpleType\SignatureOptionType::_DIRECT] 
                ),] ) )

And this one

$specialServiceRequested = new ComplexType\PackageSpecialServicesRequested();
$specialServiceRequested->setSpecialServiceTypes(SimpleType\PackageSpecialServiceType::_SIGNATURE_OPTION);
$specialServiceRequested->setSignatureOptionDetail( new ComplexType\SignatureOptionDetail( [
    'OptionType' => SimpleType\SignatureOptionType::_DIRECT,
] ));
$packageLineItem1->setSequenceNumber( 1 )
         ->setItemDescription( 'Product TEST' )
         ->setSpecialServicesRequested( $specialServiceRequested )