The DEMO version only includes 4 pages:
http://congtythietkebietthu.com
http://congtythietkebietthu.com/p/cong-ty-thiet-ke-biet-thu.html
http://congtythietkebietthu.com/p/dich-vu-thiet-ke-biet-thu.html
http://congtythietkebietthu.com/p/du-thiet-ke-biet-thu_86.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