Attempting to translate your post from Russian (is it?) returns an http code
"503 Service Unavailable
The server is not ready to handle the request. Common causes are a server that is down for maintenance or that is overloaded."
Often this seems to happen on small instances:
@FinchHaven
Are you sure it's not your server responding with that?
I didn't check it out, but I don't think remote instances (ours in this case) are supposed to translate content. I'd bet that there's a problem with translation backend on your instance. For example if it's using LibreTranslate or something like that it could be unavailable right now. Our instance uses DeepL and when I tried to translate my post just now everything was fine.