It’s been soft-pedaled, but at some point, the Kremlin paid someone to write this article:
https://www.russia-briefing.com/news/alaska-must-be-returned-to-russia-political-scientist.html/
The argument is three-fold:
(1) Alaska is geographically close to Russia;
(2) Alaska belonged to Russia in the past;
(3) Despite the Russian sale of Alaska to the U.S., the U.S. violated some alleged treaty obligation involving the treatment of Orthodox Christians, so the treaty is void and Russia’s entitled to reclaim it.
The argument is absurd, of course, but it is constructed exactly the way Russian imperial arguments are constructedin other parts of the world including Ukraine.