curl --request POST \
  --url http://localhost:8080/polls/{poll_id}/send \
  --header 'Content-Type: application/json' \
  --data '
{
  "target": "<string>"
}
'

{
  "poll_id": 123,
  "target": "<string>",
  "sent": 123,
  "failed": 123,
  "skipped": 123,
  "total": 123
}