Yes, you are able to pull the ID via API.
The CH ID of an account can be gathered using the owner ID.
https://chapi.cloudhealthtech.com/api/search?api_key={api_key}&api_version=2&page=1&name=AwsAccount&query=owner_id='{owner_id}'&fields=owner_id
Using AWS as an example, enter the owner ID where it says owner_id in the curly braces in the the string above.
For more information on CloudHealth API details, see: https://apidocs.cloudhealthtech.com/