It was easy to install and only required two steps:
- Install the App into my GitHub repo via https://github.com/apps/utterances.
- Added the following script to my blog
<script src="https://utteranc.es/client.js" repo="MonicaG/MonicaG.github.io" issue-term="pathname" theme="github-light" crossorigin="anonymous" async> </script>
See https://utteranc.es/ for more information on the settings available.