Ok, seems it’s only in Lucidchart, not Lucidspark.  I was able to switch to Lucidchart, create the diagram, then switch back to Lucidspark.

Hi ​@victor.robison, thanks for your post and for sharing a workaround in our Community! 

Indeed, if you wish to generate a diagram in Lucid using a Mermaid code, this functionality is available only in Lucidchart at the moment. Switching between Lucidchart and Lucidspark is a great workaround to make the best out of both tools in this particular case.

If you would like to see diagram as code with Mermaid in Lucidspark, you can search the Product Feedback section of this community (with the filter Topic Type = Idea) to see if it’s already been submitted. If so, please add any additional details you’d like and upvote the request - this consolidation helps to refine feedback and properly capture the popularity of the request.

If no one has submitted this idea yet, please create one of your own and be sure to include details about your use case or what you’d like to see in this experience. This will also allow other users with similar requests to discover and upvote it, then add details of their own.

Finally, for more information on how Lucid manages feedback via this community, take a look at this post.

Cheers!