Modal popup and pass value

Hi,

I am starting with Razor Pages, I have a table and each record has a "details" button, so I need to show a modal popup with the details, I used to do this in asp.net with Ajaxtoolkit ModalPopupExtender, but now I have no idea.

I have tried this sample https://softdevpractice.com/blog/razor-pages-ajax-modals-with-validation/ but no luck, I just can't make it work.

Any ideas? any tiny sample?

(Please, not MVC, that will confuse me even more)

Thanks in advance :)