The DEMO version only includes 4 pages:
https://simthanhcong.net
https://simthanhcong.net/sim-tra-gop.html
https://simthanhcong.net/dinh-gia-sim.html
https://simthanhcong.net/cam-do-sim.html

It is possible to download these free files and install them on your server, so you can test how the site works.
Visit https://www.waybackmachinedownloader.com/en/buy-wayback-machine-downloader-recover/ to buy a fully functioning site.
Go back to the index page