Regardless of which device you started on, the same Pokmon UNITE save data can be accessed from a Nintendo Switch system or a mobile device by linking the correct Nintendo Account or Pokmon Trainer Club account.
Here's how to transfer your save data for Pokmon Scarlet and Violet: Press X on the Pokmon game from the Nintendo Switch home screen on both consoles.Select Manage Software on both consoles.Select Transfer Your Save Data on both consoles.