The main extension store for the Yandex browser is addons.opera.com.
The Yandex Browser itself differs from Opera only by having more restrictions, built-in Yandex GPT, and the fact that data collection goes directly to Moscow. [Have doubts? Compare these two browsers on a virtual machine. The game of "find 10 differences" will be quite difficult...]
And who told you that this Chinese browser is Norwegian?
At least since 2016 it has officially belonged to the Chinese Opera Software ASA. And there are also Africans and Russians among the developers. And not least, that is why the Russians are making their Yandex browser based on this browser.
Browsers that will be able to shop for and even buy things such as hotel rooms, event tickets or flights all by themselves are on the way, according to Opera. Its Browser Operator is a "native" AI agent that can complete tasks in response to natural-language requests. It is backed to uphold the user's privacy and control at all times.