You must be confusing something, the auto-exploration button is the last button in the small buttons in the upper part of the screen. 
The blue button in that screenshot
Viewing post in Generic RPG Idle - Rituals & Magic comments
Something buggy though. I've tried that button already and it didn't work. (Now I've tried it again and it works)
Not sure what's causing it or what prevents it from working.
Anyway: Now that I know that it CAN work, the game is far more fun than before.
Another bug I found: I have an item "Nature Warrior of Thunder", which simply locks the game after one battle. The next battle is visible, but the game does not react to inputs. I can't even change UI screens then.