curl https://api.thanxsandbox.com/purchases \
  -X POST \
  -H 'X-ClientId: {client_id}' \
  -H 'Accept-Version: v4.0' \
  -H 'Content-Type: application/json' \
  -H 'Authorization: Bearer {access_token}' \
  -d '{
    "purchase": {
      "merchant_id":  "weoru",
      "location_id":  "hljkfd2345",
      "user_id":      "wgljsdwer23",
      "card_id":      null
      "amount":       13.45,
      "purchased_at": "2020-09-15T00:52:10.655+00:00",
      "products":     ["coffee", "pizza"]
    }
  }'

{}