Issue with the select multiple state

public function form(Form $form): Form
{
    return $form
        ->schema([
            Select::make('unique_identifier')
                ->label('Select the fields for the unique identifier')
                ->multiple()
                ->options($this->csvHeaders)
        ])
        ->statePath('data');
}

public function save()
{
    $data = $this->form->getState();
    dd($data);
}