How to apply JSON (content representations)?

I’m creating a json file with reference to the ‘content representations’ guide.
But I don’t know how to apply this.

I have a template /site/templates/bookshops.php
and I created site/templates/bookshops.json.php

Then when I connect to bookshops.json, I can connect.
But how can I represent this like bookshops.php?
Currently these two files look different.
https://seoulbookshops.kr/bookshops
https://seoulbookshops.kr/bookshops.json

The reason I want to make json is because I want to use ajax later.
The story related to this is in the question I posted before.
https://forum.getkirby.com/t/how-to-use-ajax-in-kirby3/15300

And I read this guide.
https://getkirby.com/docs/guide/templates/content-representations

I don’t really understand the question. If I got right what you said before, there is not need for the bookshops.php standard template but a snippet that is loaded when the page is first loaded, because you want to pull your content via Ajax into the homepage. For that you need an Ajax call to the content representation when the user clicks on “Bookshops” and you need content representations for the stuff you want insert when the user clicks a link.

In fact, it would make sense to reuse the initial snippet in your content representation to prevent duplicating your code.

Could you please clarify or be more specific what information is missing? Thank you.

Continued here, so closing this: How to use AJAX in kirby3