Firstly, Anki asked me if I wanted to upload or download. I did not understand what they were trying to do so I clicked download. WORST MISTAKE OF MY LIFE! I think my last sync did not include the recent cards they made or something. I clicked on download. Hence, Anki deleted my most recent deck.
Secondly, I tried to google for solutions but they did not work. I went to profiles, and then backup and chose the backup I wanted.
However, when I clicked on the backup this happened:
After that, I got the backup but it did not included the deck that was deleted.