It sounds like you’ve found a download link for in NSP format (the file format used for Nintendo Switch games) along with the 1.0.2 update.
: This specific update for River City Girls 2 was notable for addressing performance issues, specifically improving the frame rate (aiming for 60 FPS on certain platforms) and fixing various gameplay bugs reported at launch. River City Girls 2 (NSP)(Update 1.0.2).rar
: To use an NSP file, you'll typically need a modified Nintendo Switch running custom firmware (CFW) like Atmosphere. Ensure your system's "sigpatches" are up to date so the game and its update boot correctly. It sounds like you’ve found a download link