Mario Golf Super Rush has been updated to version 4.0.0 today by Nintendo. You can find out the complete patch notes from here.
The final update for Mario Golf Super Rush was released today adding two new playable characters and two new golf courses, and two new gameplay modes. There are various other fixes and adjustments added as part of the game update including several bug fixes. You can get the details on this update below, or have a look at them on the official website.