If you are playing on an emulator like Ryujinx or Suyu , follow these steps to apply the v1.4.1 update:
This format represents a dump of a physical game cartridge. It often contains only the base game, but "custom XCI" files can exist that bundle the base game with its updates and DLC into a single file.
Ensure you have the version-specific NSP update file.
This is the format used for official eShop digital downloads. It is the most common format for standalone updates and DLC.