To start the Wuchang: Fallen Feathers Huang Jian’e quest, you must acquire the Trinity Bell item. It’s dropped by a boss named Lu Hongliu in an arena in Narrow Stretch–i.e. the village near Shu Sanctum.

As for Jian’e, she’s actually inside Shu Sanctum. The first time you speak to her, she’ll give you the Zhenwu Hairpin headgear. Then, if you give her the Trinity Bell, she’ll hand over 1x Recovery Pill and the Greet emote. This also continues her quest.

Note: Do not progress further into the campaign without giving the Trinity Bell to Huang Jian’e. If you fail to give her this item, she’ll turn hostile by the time you reach Mt. Zhenwu – Refugee camp, and you’ll have no choice but to kill her.