Even during the trial period, Syncfusion’s libraries include logic that checks for a valid license at runtime. Without the key, your application will throw a LicenseException or a Syncfusion.Licensing.LicenseException when you try to use a control like a DataGrid, Chart, or Scheduler.
Unlike some libraries that work immediately upon installation via NuGet or NPM, Syncfusion requires a registered license key to: syncfusion trial license key