public function recipient_sso_link($credential_id = null, $recipient_id = null, $recipient_email = null, $wallet_view = null, $group_id = null, $redirect_to = null){

        $data = array(
            "credential_id" => $credential_id,
            "recipient_id" => $recipient_id,
            "recipient_email" => $recipient_email,
            "wallet_view" => $wallet_view,
            "group_id" => $group_id,
            "redirect_to" => $redirect_to,
        );

        $data = $this->strip_empty_keys($data);

        $client = new \GuzzleHttp\Client();

        $response = $client->post($this->api_endpoint.'sso/generate_link', array(
            'headers' =>  array('Authorization' => 'Token token="'.$this->getAPIKey().'"'),
            'json' => $data
        ));

        $result = json_decode($response->getBody());

        return $result;
    }