Trump, as he often does, claimed that he invented the phrase “fake news.” (Indeed, he has said elsewhere that “fake news” is “one of the greatest of all terms I’ve come up with.”) In fact, “fake news” first entered the language in the late nineteenth century; it came to the fore most recently as a way of describing fabricated stories, not a few of them engineered for profit in Russia and other foreign countries. Trump adopted the phrase for his own purposes during the 2016 campaign and has deployed it as a weapon in his broader attempt to delegitimize the news outlets—the Times, the Washington Post, CNN, and many more—that he views as political adversaries, and to create a kind of parallel universe of “alternative facts” and realities.
Trump didn't start using "fake news" until 2017. It wasn't part of the campaign.