Participant Update - Category
To modify the category associated with an existing account, employ the /api/v2/account/set endpoint. To modify a specific visitor, identify them using one of EP's accepted matching methods and employ the subsequent fields:
event_id:
The unique identifier for the event. (integer)id:
Account ID (integer)category_id:
User“s category (integer)

Notice: Participant Category identifiers are available within the Registration settings under Visitor and then Participant Categories