Set up local proxy
Mendix: “For local development, the easiest solution is to set up a local proxy that secures the connection towards your local Mendix application.” How can I set up a local proxy?
Since you used a quote from the documentation without mentioning what you're trying to do, I assume you're trying to use the Barcode Scanner?
To use it locally, you need an https connection. The answers in this forum thread explain some ways to achieve that.