The “divest or ban” TikTok bill has passed. Now the legal battle begins.

The U.S. government has officially enacted a measure that will limit TikTok‘s power and reach — if it holds up in court. The ByteDance-owned app has vowed to wage a legal battle after President Biden approved a law that will ban TikTok in the U.S. if ByteDance does not divest it first.

The divest-or-ban bill, authored by Representatives Mike Gallagher (R-WI) and Raja Krishnamoorthi (D-IL), is the latest in a series of Congressional attempts to control Beijing-based ByteDance and its buzzy short-form video app. It was introduced as a successor to the RESTRICT Act, which seemed destined for President Biden’s desk before it was tabled and retooled.

The latest piece of TikTok-oriented legislation did not meet the same fate as its predecessor. Though some Senators called for the bill’s vote to be delayed so that a public hearing could occur, the Senate ultimately followed the House’s lead and approved the measure on April 23. The next day, President Biden signed the bill — which includes a foreign aid package earmarked for Israel, Ukraine, and Taiwan — into law.

With the law approved, ByteDance will have 270 days to divest TikTok. President Biden can extend that timeline by three months if ByteDance is making progress on its divestment plan. When the window elapses, if ByteDance has not handed TikTok off to a U.S.-based parent, an outright ban at the national level will be the next step.

TikTok, however, will not accept the new law without a fight. Days before the Senate vote, the app shuffled up its legal team, with general counsel Erich Andersen stepping down. Vice President of Public Policy Michael Beckerman then revealed TikTok’s intention to mount a legal challenge against the divest-or-ban law.

“Thankfully, we have a Constitution in this country, and people’s First Amendment rights are very important,” Beckerman said in an interview with a creator. “We’ll continue to fight for you and all the other users on TikTok.”

A challenge on First Amendment grounds sounds similar to the strategy TikTok used to push back against a Montana law that attempted to restrict the app’s presence within American app stores. That effort was aided by creators, who also sued Montana over its restrictive measure. At the federal level, TikTok will continue to rely on the support of its creator community, which has predominantly opposed Congressional efforts to limit the app.

Even with a court battle taking shape, ByteDance could still assuage lawmakers by divesting TikTok. The Chinese government’s opposition to the new law makes that plan a longer shot than it otherwise would be, but potential buyers are nevertheless lining up. Film financier and former Trump cabinet member Steven Mnunchin is one investor with eyes for a TikTok acquisition.