curl --request POST \
  --url https://api.example.com/api/v1/campaign/schedule/ \
  --header 'Content-Type: application/json' \
  --header 'X-Api-Key: <api-key>' \
  --data '
{
  "campaign_uid": "<string>",
  "start_date_ts": 123
}
'

{
  "message": "<string>"
}