[On NBC’s ‘Dancing With Myself,’ TikTok-Like Dances Meet Network TV] TikTok gave U.S. lawmakers more details in a letter dated Thursday about how it plans to keep data about its American users separate from ByteDance, its Chinese parent company, aiming to combat concerns that the video app poses a national security risk. In a letter to nine Republican senators, Shou Zi Chew, TikTok’s chief executive, explained how the company would operate the app from servers controlled by Oracle, the U.S. cloud computing giant. TikTok would be run from the American company’s machines and audited by a third party, Mr. Chew…