How to reference built-in shape library shapes

Hi,

I'm using the Lucid Standard Import API (POST /documents with .lucid format) to programmatically create architecture diagrams. I can successfully create shapes using basic types like rectangle, ellipse, and diamond, but I need to use shapes from the AWS Architecture 2021 shape library (EC2, Lambda, VPC, API Gateway, Cognito, NAT Gateway, etc.).

I've tried the following approaches without success:

1. Setting "type" to AWS-specific names ("ec2", "AWSec2", "AWS2021::Compute::EC2", etc.) → "Invalid shape type"

2. Adding "class": "AWSComputeEC2InstanceBlock" or "customType": "AWS2021EC2Instance" on the shape object → silently ignored, renders as DefaultSquareBlock

3. Adding "shapeLibrary", "blockType", or "templateId" properties → also ignored

The only workaround I found is using "fill": { "type": "image", "url": "..." } with external PNG URLs of the AWS icons, but this is fragile and doesn't give me the native Lucid AWS shapes with their built-in behavior.

Is there a way to reference shapes from Lucid's built-in shape libraries (specifically AWS Architecture) through the Standard Import format? If so, what is the correct syntax for the type field or any other property?

Thanks!