code: public function updatePush( \Psr\Http\Message\ServerRequestInterface $request, \Psr\Http\Message\ResponseInterface $response )
  	{
  		$params = (array) $request->getAttributes() + (array) $request->getParsedBody() + (array) $request->getQueryParams();
  
  		if( isset( $params['reference'] ) )
  		{
  			$response = parent::updatePush( $request, $response );
  			$response = $response->withBody( $response->createStreamFromString( 'TSOK' ) ); // payment update successful
  		}
  
  		return $response;
  	}
docs: Updates the order status sent by payment gateway notifications
  
  @param \Psr\Http\Message\ServerRequestInterface Request object
  @return \Psr\Http\Message\ResponseInterface Response object