The court is hearing oral arguments on TikTok’s bid to block a law that would lead to its ban in the U.S. starting Jan. 19 if it isn’t sold by its Chinese owner.

Justices will hear arguments in two consolidated cases taking aim at the federal law, which requires Chinese-owned ByteDance to divest from TikTok, or else TikTok will be banned from U.S. app stores and from being hosted by American internet service providers.