Web components of Geotrek.
You can use a complete app or each component independantly.
The api you want to use had to authorize your domain.
Copy-paste this inside <head></head>
<link rel="stylesheet" href="https://rando-widget.geotrek.fr/latest/dist/geotrek-rando-widget/geotrek-rando-widget.css" />
<script type="module" src="https://rando-widget.geotrek.fr/latest/dist/geotrek-rando-widget/geotrek-rando-widget.esm.js"></script>
<script nomodule src="https://rando-widget.geotrek.fr/latest/dist/geotrek-rando-widget/geotrek-rando-widget.js"></script>
The api you want to use had to authorize geotrekce.github.io.
You can explore Geotrek Rando Widget and create your own component here.
Once you made your component, you can get the code to copy-paste by clicking on Docs then Show code.