curl --request POST \
  --url https://api.vantage.sh/v2/managed_accounts \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "name": "<string>",
  "contact_email": "<string>",
  "access_credential_tokens": [
    "<string>"
  ],
  "billing_rule_tokens": [
    "<string>"
  ],
  "email_domain": "<string>"
}
'

{
  "token": "acct_ace620fc3d602740",
  "name": "New Managed Account",
  "contact_email": "admin@acme.com",
  "parent_account_token": "acct_e6baa6dcf81b4e20",
  "access_credential_tokens": [
    "accss_crdntl_72a8c8ab1d6c9d2c"
  ],
  "billing_rule_tokens": [],
  "email_domain": null
}