Cannot create quiz questions programmatically

Please notice: I would like to create a multiple-choice question programmatically.

I was able to do it like this:

      $a = Paragraph::create([
        'type' => 'multichoice',
        'multichoice_correct' => 1,
        'multichoice_answer' => 'Alternative A',
        'multichoice_feedback_chosen' => 'You chose A',
        'multichoice_feedback_not_chosen' => 'You did not choose A',
        'multichoice_score_chosen' => 1,
        'multichoice_score_not_chosen' => 0,
      ]);
      $a->save();

      $b = Paragraph::create([
        'type' => 'multichoice',
        'multichoice_answer' => 'Alternative B',
        'multichoice_feedback_chosen' => 'You chose B',
        'multichoice_feedback_not_chosen' => 'You did not choose B',
        'multichoice_score_chosen' => -1,
        'multichoice_score_not_chosen' => 0,
      ]);
      $b->save();

      $c = Paragraph::create([
        'type' => 'multichoice',
        'multichoice_answer' => 'Alternative C',
        'multichoice_feedback_chosen' => 'You chose C',
        'multichoice_feedback_not_chosen' => 'You did not choose C',
        'multichoice_score_chosen' => -1,
        'multichoice_score_not_chosen' => 0,
      ]);
      $c->save();

      $question = QuizQuestion::create([
          'title' => 'MCQ 1 Title',
          'type' => 'multichoice',
          'choice_multi' => 0,
          'choice_random' => 0,
          'choice_boolean' => 0,
          'body' => 'MCQ 1 body text',
        ]);
      $question->get('alternatives')->appendItem($a);
      $question->get('alternatives')->appendItem($b);
      $question->get('alternatives')->appendItem($c);

      $question->save();

Found code examples in the automated tests. See quiz/modules/quiz_multichoice/tests/src/Functional/QuizMultichoiceTestCase.php