curl --request POST \
  --url https://api.hubapi.com/marketing/v3/transactional/smtp-tokens \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "campaignName": "<string>",
  "createContact": true
}'

{
  "campaignName": "<string>",
  "createContact": true,
  "createdAt": "2023-11-07T05:31:56Z",
  "createdBy": "<string>",
  "emailCampaignId": "<string>",
  "id": "<string>",
  "password": "<string>"
}