You probably want to be running the official duo SDK instead: https://github.com/duosecurity/duo_api_golang
Duo Security two-factor authentication for Go web applications. It uses Duo's official JavaScript widget in an iframe, and a high-level API to authenticate users with Duo’s 2FA.
In order to use this you must have a Duo account and create a new application in your account. You will then be given keys to use for authentication.
There is a functional demo app in this repository.