Yes. Requires the DLC. Go to the Isle of Armor. Meets someone looking for Alolan Digletts scattered throughout the area. Must find 100 Alolan Digletts (out of 150) and have chosen the Water starter (Sobble). Supposedly reaches up to 106 Alolan Digletts without the ability to traverse over water. (Cannot confirm that, though.)
Could also acquire one via trading. Allows you to own Pokemon introduced with the DLC, even if you did not buy it.
Option 1: Access GTS through the Pokemon Home Switch + smartphone apps (no subscription necessary).
Option 2: Arrange a trade with someone online (or get lucky with Surprise Trade). Requires a Nintendo Switch Online subscription (or trial version), however.