curl --request POST \
  --url https://api.charp.ai/campaigns/{campaign_id}/schedule \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "start_time": "2023-11-07T05:31:56Z",
  "end_time": "2023-11-07T05:31:56Z"
}'

{
  "campaign_id": "<string>",
  "status": "<string>"
}