A group of lawmakers is mounting a last-ditch effort to delay a TikTok ban from going into effect on Sunday and give the company more time to find an American buyer and evaluate the risks the app poses to national security.

The plea to President Joe Biden comes after Sen. Ed Markey (D-MA) introduced a bill to extend the deadline to sell TikTok by another 270 days, stressing the online “communities cannot be replicated on another app.” An attempt to pass the bill by unanimous consent was blocked in the Senate on Wednesday, leaving lawmakers opposed to the ban with few options before it takes effect.