First build the Reagent app in the folder examples/client-side/reagent-inertiajs:
$ npx shadow-cljs release app
or for development with hot reloading and REPL:
$ npx shadow-cljs watch app
This will create the file /js/app.js
that will be included in the html page served by the backend.
This entry point is shared among several examples, so it live in the examples/shared-resources.
Then run the server:
$ clj -M:run
Now acces the app at: http://localhost:3000/ and then experiment!