curl --request POST \
  --url http://localhost:8080/promo-groups \
  --header 'Content-Type: application/json' \
  --data '
{
  "name": "<string>",
  "period_discounts": {
    "1": 10,
    "6": 20
  },
  "server_discount_percent": 0,
  "traffic_discount_percent": 0,
  "device_discount_percent": 0,
  "auto_assign_total_spent_kopeks": 123,
  "apply_discounts_to_addons": true,
  "is_default": false
}
'

{
  "id": 123,
  "name": "<string>",
  "server_discount_percent": 123,
  "traffic_discount_percent": 123,
  "device_discount_percent": 123,
  "apply_discounts_to_addons": true,
  "is_default": true,
  "period_discounts": {},
  "auto_assign_total_spent_kopeks": 123,
  "members_count": 0,
  "created_at": "2023-11-07T05:31:56Z",
  "updated_at": "2023-11-07T05:31:56Z"
}