This plugin adds loading="lazy" to all img and iframe tags on your Jekyll site. No configuration is needed. If a loading attribute is already present nothing is changed. Note that the github-pages gem runs in safe mode and only allows a defined set of plugins. To use this gem in GitHub Pages, you need to build your site locally or use a CI (e.g. Github Workflow) and deploy to your gh-pages branch. In case you want to prevent loading some images/iframes lazily, add loading="eager" to their tags...