Tome of the Sun – When you level a clan you must have ingots, resource and the 3rd thing to level up. How do you get that 3rd thing?

The 3rd thing is to increase the Prosperity of the clan. 
The Prosperity will be increased when the clan members finish the clan quests, make donations, or stay online. When the clan is leveled up, the prosperity will also be increased accordingly. Please note that the total online time in the clan of a new clan member should be more than 24 hours so that they can begin to help increase the prosperity.