curl --request POST \
  --url https://{cluster}.voucherify.io/v1/loyalties/{campaignId}/earning-rules/{earningRuleId}/enable \
  --header 'Authorization: Bearer <token>' \
  --header 'X-App-Id: <api-key>' \
  --header 'X-App-Token: <api-key>'

{
  "id": "ern_raVUcdXruvXGuzm682ESrAzt",
  "created_at": "2022-11-24T09:03:14.534Z",
  "updated_at": "2022-11-25T14:07:39.460Z",
  "loyalty": {
    "points": 20,
    "type": "FIXED"
  },
  "event": "order.paid",
  "source": {
    "banner": "Order has been paid",
    "object_id": "camp_fkZ28pe7DUAEmmabofkxHI8N",
    "object_type": "campaign"
  },
  "active": true,
  "start_date": "2022-11-23T00:00:00.000Z",
  "expiration_date": "2022-11-30T00:00:00.000Z",
  "validity_day_of_week": [
    1,
    2,
    3,
    4,
    5
  ],
  "object": "earning_rule",
  "automation_id": "auto_MbEIyLbn7pHyba5Qw5eeb35L",
  "metadata": {
    "Type": "Order has been paid - Fixed"
  }
}