Wuthering Waves 3.8 preview codes: three codes and their deadline
Three global preview codes each include 100 Astrites and expire on November 8, Pacific Time.

The global Wuthering Waves 3.8 preview broadcast shared three limited-time redemption codes: TRAINOFSOULS, BLOOMINGFLOWERS and SCHOOLLIFE. The official graphic shows 100 Astrites and other materials for each code, for 300 Astrites across all three.

Kuro’s November 6 post says the codes are valid until November 8 at 07:59 Pacific Time. That is 15:59 UTC, 22:59 in western Indonesia and Thailand, and 23:59 in the Philippines and UTC+8 regions on the same date. The official notice asks players to redeem them in the game before they expire.
Enter the server where your character is located, then enter the codes one at a time under Settings → Other → Redemption Code. Rewards depend on the actual redemption result. These are codes for Wuthering Waves itself, separate from codes for the Wuwa Tappo desktop app.
Official Wuthering Waves code announcement




