In order to file documents under seal, you either have to have a case that is sealed per an order of the lower court or a matter that is deemed confidential by law. When filing to NYSCEF, you need to check a box asking if this is a sealed matter. Once you click that, it will ask you for the order on cases that were sealed at the lower court proceedings at the request of one or all of the parties. If the case is deemed sealed by law, then you will not need to do anything more than upload your document as the case was automatically sealed by the court. In cases that the lower court did not sealed the proceeding or they are not confidential in nature, but the parties want them sealed at the appellate level, a formal motion must be filed with the appellate division requesting the sealing of all or partial documents on appeal.