Place your Nintendo keys in the bin folder of the SAK directory.
If you are looking for a "patched" update, you specifically want v1.0.2 (v65536) with correct Sigpatches. lego city undercover switch nsp update patched
We do not condone piracy. The only legal way to use a patched NSP is to dump your own cartridge using a tool like NXDumpTool and then apply the official Nintendo update (downloaded via a Switch DNS sniffer) to your own dump. Downloading pre-patched NSPs from torrent sites violates copyright law. Place your Nintendo keys in the bin folder