The best way to get started with Keycloakify is to study and play around with the starter project.
The README details everything there is to know and there is a lot of comments in the code to help you figure things out.
{% embed url="https://github.com/codegouvfr/keycloakify-starter" %}
Alternatively, one of the main contributors of the project wrote a tutorial on his blog article. Check it out!
{% embed url="https://youtu.be/x3ux2JM1Bxk" %} Introduction video + blog post {% endembed %}
{% embed url="https://youtu.be/WMyGZNHQkjU" %} A video to give you confidence that this thing actually works {% endembed %}