DLC is free to claim until March 16, will be paid afterwards. Game not needed to claim on Xbox or Playstation. Steam requires the game to claim DLC.
Xbox/Game Pass: https://www.xbox.com/games/store/armure-baihu/9N97DVTC0S69/0010
PlayStation: regional-free search link, first search result is the DLC for your region - https://store.playstation.com/search/wo%20long%20fallen%20dynasty%20baihu%20armor
Steam: https://store.steampowered.com/app/2205890/Wo_Long_Fallen_Dynasty_Baihu_Armor/