Insided Connector for Workato - Sandbox setup?

I am trying to set up a connection between Workato and Gainsight CC Sandbox to automate some things.  When I tried to set up a connection, it gave me this error:

Does this thing still work, and can it be used to connect to cc sandbox?

The AI Answers search said that this connector can only be used in production, but that sounds crazy to me!  Has anyone tried this?