The example in https://eidivandiomid.medium.com/diagram-as-code-using-structurizr-c41f6dd0738f worked for me. I'm rendering using the docker Structurizr lite.

I must say, if you are using the C4 DSL extension in VS Code, it will mark errors in all the other dsl files, complaining of a missing "workspace" token. something similar to:

Unexpected tokens (expected: workspace) at line 1 of your path\otherfile.dsl: Product = softwareSystem "Product System" {

but the files are correctly rendered by the server.