Get Douyin content author portrait

Returns Douyin creator (author) portrait for a category (i.e. profile of users who post in this category). Send tag_id (Category ID, required, does NOT support 0=all. Get fu..), end_date (End date YYYYMMDD); optional period. Returns creator portrait: gender, age group, region, device, active time distributions. period: "week" (end_date must be a Sunday) or "month" (end_date must be month-end, e.g. 20260331).