Guild Wars 2

How do you earn the Bonus Chest ? How many you can get daily ?

You get a bonus chest once per day (after reset) for each reward tier boss stage completed. You can get 6 in total:
1-9
10-19
20-29
30-39
40-49
50

Coco is mostlyy right… however, the reward tiers are actually:

1-10
11-20
21-30
31-40
41-50

Also, you can only gain up to your personal level. So if your personal level is 15 you can do a 50 but you’ll just get the 11-20 chest, then you can do a 1-10 and get that chest.

So you have to do each level range for it’s respective chest but you cap out at your level even if you do one higher than that.