get all client details - further declarations necessary?

[cluster]

I'm working on a provisioning module that uses a Rest API, connection already works...
I would like to pass all client details (address, zip, city, phone etc.) to the panel via API, is it sufficient as listed below or do all client variables have to be declared again separately?
as an example:

"first_name"=> $client->first_name,

    public function addService(
        $package,
        array $vars = null,
        $parent_package = null,
        $parent_service = null,
        $status = 'pending'
    ) {
        $row = $this->getModuleRow();

        if (!$row) {
            $this->Input->setErrors(
                ['module_row' => ['missing' => Language::_('kh.!error.module_row.missing', true)]]
            );

            return;
        }

// ...
// my question refers to this
    $data = array(
       "username"=> $username,
       "email"=> $client->email,
       "password"=> $this->generatePassword(),
       "id_hosting_plan"=> $package->meta->template,
       "is_suspended"=> false,
       "suspend_on"=> null,
       "delete_on"=> null,
       "send_login_credentials"=> false,
       "create_system_domain"=> false,
       'contact_data'=>[
       "first_name"=> $client->first_name,
       "last_name"=> $client->last_name,
       "company"=> $client->company,
       "telephone"=> $client->phone,
       "address"=> $client->address1,
       "city"=> $client->city,
       "zip"=> $client->zip,
       "state"=> $client->state,
       "country"=> $client->country,
       "client_id"=> $client->client_id
       ]
    );

// ...

    public function getClientAddFields($package, $vars = null)
    {
        Loader::loadHelpers($this, ['Html']);

        $fields = new ModuleFields();

        // Create domain label
        $domain = $fields->label(Language::_('kh.service_field.domain', true), 'kh_domain');
        // Create domain field and attach to domain label
        $domain->attach(
            $fields->fieldText(
                'kh_domain',
                (isset($vars->kh_domain) ? $vars->kh_domain : ($vars->domain ?? null)),
                ['id' => 'kh_domain']
            )
        );
        // Set the label as a field
        $fields->setField($domain);

        return $fields;
    }