Assign a promotion

Promotions can be assigned to contacts either though a file import, manually in the Engage UI, or by using this API endpoint:

POST /api/v3/promotion-assignments

With the following kind of payload:

{
  "contactId": "e0e63d15-1881-4f9a-9ce1-94c3e21c6f47",
  "promotionId": "132aa326-fa89-4a8b-af9f-0b232157f8a2"
}