curl --request POST \
  --url https://{notifuseDomain}/api/broadcasts.cancel \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "workspace_id": "ws_1234567890",
  "id": "broadcast_12345"
}
'

{
  "success": true
}