I am new to the game, just over a month, so maybe I do not know where to look. I have been doing the damage shown for drops but have not seem to have seen any. Where do they show up at?
If you hit enough damage, the next day the button to fight is replaced by a button to collect your rewards. You can't fight again until you have gotten the chest, it's impossible to miss.
Maybe you're fighting a different difficulty than you think?
okay I fought easy and have 922k damage. this should be good enough for the adept chest. You are saying the Battle key should be replaced tomorrow with a button to collect the reward? This has been done before and I have never seen such a thing.