When does Sword Art Online: Alicization return?

The third season of the Sword Art Online anime television series is based on the light novel series written by Reki Kawahara and illustrated by abec. It covers the first part of the "Alicization" arc and adapts from the novel's ninth volume, Alicization Beginning, to the fourteenth volume Alicization Uniting. The anime series extends to the fourth season, which adapts the story from Alicization Invading to the eighteenth volume. The first opening theme of the series is "Adamas" by Lisa, and the first ending theme is "Iris" by Eir Aoi.