שמעתי שהמילה "just" מבולבלת הרבה דוברי שפות אחרות, בגלל שיש לה משמעויות רבות (שש לדעתי)
The vowels aren't strictly necessary, and if you ever get marked wrong and the only "mistake" is a missing niqqud, be sure to report it.
That said, if you want to add them, there is a way to do it, depending on your OS. For Windows it's allegedly Caps Lock + Shift, for Mac it's the Option key, and in either case you then press a key on the number row and it'll add a niqqud to the letter before your cursor.
Allegedly. I haven't gotten it to work, myself.
Marked wrong for "only he doesn't make this." How can one tell when to use "do" and "make" since they're both written the same way on DL. Don't know if that's the way they're written in Hebrew as well.