curl --request POST \
  --url https://app.blogbowl.io/api/v1/newsletters/{newsletter_id}/subscribers \
  --header 'Content-Type: application/json' \
  --data '
{
  "email": "<string>"
}
'

{
  "id": 123,
  "email": "<string>",
  "verified": true,
  "active": true,
  "status": "<string>",
  "newsletter_id": 123,
  "verified_at": "<string>",
  "created_at": "<string>",
  "updated_at": "<string>"
}