Houfy non any longer available

Does anyone have experience with «HOUFY». In fact I wanted to implement it on a site, but as I klicked on the monetarise button houfy it came a site with a message «page not found». Looking on the internet houfy is absolutely not discoverable. Has this company closed their services?
Appreciate if someone could give me a hint.

Houfy is still operating.
This link explains how to implement their apps into HTML websites.

Hello MiWe, thanks a lot for your hints. Really helpful.