curl --request GET \
  --url https://api.ahasend.com/v2/accounts/{account_id}/smtp-credentials/{smtp_credential_id} \
  --header 'Authorization: Bearer <token>'

{
  "object": "smtp_credential",
  "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "created_at": "2023-11-07T05:31:56Z",
  "updated_at": "2023-11-07T05:31:56Z",
  "name": "<string>",
  "username": "<string>",
  "sandbox": true,
  "scope": "global",
  "domains": [
    "<string>"
  ]
}