Is there any way to do keyword searches any longer? What would be needed to restore that functionality?

A few years ago when I first learned of sci-hub, I was able to do keyword searches that would return lists of papers that had those keywords — you know, like any other search engine, such as Google.

That suddenly stopped working maybe a couple of years ago, and only a DOI search for a single paper would work any longer.

Does keyword searching exist any longer? Is it just me? I just use the main web page at sci-hub dot whatever; can keyword searching be done through some other interface that I don’t know about?

If it’s down for everyone, why was it shut off, and what would they need to be able to restore the functionality? It really was a much better search engine for that sort of thing than Google, which returns tons of garbage websites that hide the few research papers that are searchable. Is it just a matter of money, or of computing resources, or did they run into technical trouble, or what?