Making custom advancement which you get after finishing building a certain things?

Hi, Im new to datapacks and i was wondering. Is it possible to make an advancement which you get after finishing simple skyblock-like cobblestone generator? Are there some conditions i can use for that or its not possible? What i would like to make is getting advancement when water meets lava and im not sure how to begin or what conditions i should use. Sorry if i used wrong tag, im not sure which one i suppose to use since there is no advancement tag.