Material Polyester, Capacity 13L, Closure Type Magnetic attraction.
Basically copy coupon, view price history or create e-mail price alert. Let’s see what best price is ATM.
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($41.39): BGOD1
2. ($42.77): aff7off
you should apply the coupon in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): 99a5c13, 99a5co, 502C6B, e2bcea, TTxBG10, ILOVESDB0, BG13LMochila, 2019SPEDM
(these coupons are old, so probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for Xiaomi Urevo 13L College Backpack Yellow. The lowest price was: $30.3.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).