new action template nicht gefunden

Hallo,
dieser Controller gibt mir die Fehlermeldung: Sorry, the requested view was not found.

The technical reason is: No template was found. View could not be resolved for action "new" in class "CovisionPDFWriter\Covisionpdfwriter\Controller\CovisionPDFFormController".

Wie kann ich die newAction configurieren?

Hier der Code

<?php
namespace CovisionPDFWriter\Covisionpdfwriter\Controller;

/***
 *
 * This file is part of the "CovisionPDFWriter" Extension for TYPO3 CMS.
 *
 * For the full copyright and license information, please read the
 * LICENSE.txt file that was distributed with this source code.
 *
 *  (c) 2020 Anselmo Cotellessa &lt;anselmo.cotellessa@covisionmedia.com&gt;, Covisionmedia
 *
 ***/

/**
 * CovisionPDFFormController
 */
class CovisionPDFFormController extends \TYPO3\CMS\Extbase\Mvc\Controller\ActionController
{
    /**
     * action new
     *
     * @return void
     */
    public function newAction(\CovisionPDFWriter\Covisionpdfwriter\Domain\Model\CovisionPDFForm $newAction = NULL)
    {
        $this->view->assign('newCovisionPDFForm', $newAction);
    }

    /**
     * action create
     *
     * @param \CovisionPDFWriter\Covisionpdfwriter\Domain\Model\CovisionPDFForm $newCovisionPDFForm
     * @return void
     */
    public function createAction(\CovisionPDFWriter\Covisionpdfwriter\Domain\Model\CovisionPDFForm $newCovisionPDFForm)
    {

        $this->covisionPDFFormRepository->add($newCovisionPDFForm);
        $this->redirect('list');
    }

    /**
     * action edit
     *
     * @param \CovisionPDFWriter\Covisionpdfwriter\Domain\Model\CovisionPDFForm $covisionPDFForm
     * @ignorevalidation $covisionPDFForm
     * @return void
     */
    public function editAction(\CovisionPDFWriter\Covisionpdfwriter\Domain\Model\CovisionPDFForm $covisionPDFForm)
    {
        $this->writePDF($covisionPDFForm);
    }

    /**
     * action update
     *
     * @param \CovisionPDFWriter\Covisionpdfwriter\Domain\Model\CovisionPDFForm $covisionPDFForm
     * @return void
     */
    public function updateAction(\CovisionPDFWriter\Covisionpdfwriter\Domain\Model\CovisionPDFForm $covisionPDFForm)
    {

        $this->covisionPDFFormRepository->update($covisionPDFForm);
        $this->redirect('list');
    }

    /**
     * action delete
     *
     * @param \CovisionPDFWriter\Covisionpdfwriter\Domain\Model\CovisionPDFForm $covisionPDFForm
     * @return void
     */
    public function deleteAction(\CovisionPDFWriter\Covisionpdfwriter\Domain\Model\CovisionPDFForm $covisionPDFForm)
    {

        $this->covisionPDFFormRepository->remove($covisionPDFForm);
        $this->redirect('list');
    }

    /**
     * @param $formInputs
     */
    public function writePDF($formInputs)
    {
        $pdf = new FPDF();
        $pdf->AddPage();
        $pdf->Output('I', 'filadmin/user_upload/test/test.pdf');
    }

    /**
     * action list
     *
     * @return void
     */
    public function listAction()
    {
        $covisionPDFForms = $this->covisionPDFFormRepository->findAll();
        $this->view->assign('covisionPDFForms', $covisionPDFForms);
    }

    /**
     * action show
     *
     * @param \CovisionPDFWriter\Covisionpdfwriter\Domain\Model\CovisionPDFForm $covisionPDFForm
     * @return void
     */
    public function showAction(\CovisionPDFWriter\Covisionpdfwriter\Domain\Model\CovisionPDFForm $covisionPDFForm)
    {
        $this->view->assign('covisionPDFForm', $covisionPDFForm);
    }
}

Ich habe es jetzt geschafft, das Template aufzurufen (im Template registriert)
nun habe ich ein anders Problem. Bei den Bilduploads erscheint der Hinweis: File upload is not implemented! Außerdem gibt mir beim Abschicken des Formular typo3 ein Fehler aus.

Fragen: Wie kann ich den Upload implementieren? Wie kann ich ausführliche Fehlermeldungen im Backend erzwingen?