The free Welcome Back Gift pack in the shop offers a backpack as well as the advertised item:
The end date says it’s available until May 18, 2020 12:00 AM (UTC), May 18, 2020 2:00 AM (Europe: Brussels), May 17, 2020 8:00 PM (America: New York), May 17, 2020 5:00 PM (America: Los Angeles), May 18, 2020 10:00 AM (Australia: Canberra).
