What is the test for a motion to compel arbitration de novo when the claim is based on a legal conclusion about whether the parties contractually bound themselves to arbitrate?

We review the district courts denial of a motion to compel arbitration de novo where the denial is based on a legal conclusion about whether the parties contractually bound themselves to arbitrate. See Meyer v. Uber Techs., Inc ., 868 F.3d 66, 7273 (2d Cir. 2017). Since the district courts conclusions regarding notice and assent were based on undisputed facts, those conclusions are also subject to de novo review. Id . at 73 (holding de novo review appropriate where the evidence "consists exclusively of screenshots from the Web site and order confirmation email, and the authenticity of these screenshots is not subject to factual dispute").