I see. I just took a quick look at Viber and from what I can tell it might not be possible. Regardless, you can still ask using either Forum for Discussions. They should be able to tell you for sure. I suggest posting using Forum or Discussions because users will be made aware of your post. If you use a talk page like your friend, you will be left waiting for someone to discover your post.
Well, given that I can't read Russian, I have never used Viber, and it seems I can't get to any page like the one you are showing, it is hard for me to say for sure. However, if I had to guess, it looks like that page is giving you a QR code you can use to join. As far as I know, most desktops can't use QR codes. Even if they could, it wouldn't change whether or not the desktop application can use invite links. I don't know. Maybe something is getting lost in translation because it seems we aren't understanding each other too well.