In the challenge you will get to the chest first. When you have reached to the chest and passed that level, a couple of levels further away you should see the key when looking at the map.
You will also see a timer on the key on the map which shows within what time you will need to get to that level.
If you get to the level where the key is before the time has run out, the chest will then open and give you the rewards from it.
In the challenge you will get to the chest first. When you have reached to the chest and passed that level, a couple of levels further away you should see the key when looking at the map.
You will also see a timer on the key on the map which shows within what time you will need to get to that level.
If you get to the level where the key is before the time has run out, the chest will then open and give you the rewards from it.