When working with Api OK, when I send a comment or create an album with Cyrillic in the title, it is not decoded on their website, why?

Question

C++ / C#

When I add a comment in English or numbers, everything is fine.
When I send a comment in Russian, first, in order for the request to be correct, I do it, and it turns out that the site displays just the result of this method, that is, "% D0% 9F% D0% B0% D0% BF% D0% B0% D0% BC ". What is the problem, am I sending it wrong, or is it not decoded for some reason? HttpUtility.UrlEncode("Папам")