Ok, I don't understand any Russian :) but it seems there is a plugin on the Opera addons store (https://addons.opera.com/ru/extensions/details/wallabagger/?...). This addon is mentioned on the following Wallabag page (https://www.wallabag.org/blog_index.html). Hope it works.

EDIT: you can also have a look at Respawn (https://github.com/broncowdd/respawn). It is not as advanced as Wallabag, but it also saves a copy of any webpage to your own server.