Error when accessing base controller variable

Your issue is the class constructor will run before initController method. Use this instead.

PHP Code:

class AccountController extends BaseController
{
    public function initController(\CodeIgniter\HTTP\RequestInterface $request, \CodeIgniter\HTTP\ResponseInterface $response, \Psr\Log\LoggerInterface $logger)
    {
        parent::initController($request, $response, $logger);

        $this->template = new TemplateRenderer($this->settings);
    }