The workflow validator app doesn't work when running as a customer in the creation transition in Jira Service Management

Hello team! We’re researching Forge to resolve an issue for a major client that uses Jira Service Management. We’ve developed an app using the workflowValidator module. The goal is to be able to use it in the creation transition. We saw in the documentation that it’s possible to use lambda functions for more complex validations, and that’s exactly what we need. Here’s the problem:
When we create a ticket with a licensed user, the transition runs and the application works correctly. However, when we do so with a customer user (unlicensed), the application throws the following error (attachment).
Is this a bug? We need the application to always run during the transition, even when customer users do so, because the application is designed for them.
Thank you very much.
PS: If you want to reproduce the issue, just create an application using the Forge CLI and select the Workflow Validator template. Then add the validation to the creation transition and test that it runs with a customer user.

Error:

Error addon forge

I don’t think it’s available for unlicensed JSM users as per the docs.