For that, you first have to unlock metal (get 12 earth) and then spend the metal on activating temporary automation (bottom right corner of each action). Each second of temporary automation contributes to ticking down that timer. If you have multiple active the timer ticks down accordingly faster, so don't be afraid of activating as much temporary automation as you can afford.
Furthermore, the effects of fire prestige only take effect after purchasing the second transcend upgrade in the air tab.
I'll admit it's tough to understand what to do. It wasn't intuitive to me either.