To get those working basically all you need to worry about is getting the "istats" command working in terminal. AQT uses that command internally and essentially is just a mini terminal display. Once you can get this working, AQT should either connect in a breeze or even automatically.
I'm actually not versed in terminal either ahah, before catalina it was very easy. I only got mine working with pure, and i actually mean pure chance, I don't even know where iStats is installed.
So, iStats is a "gem" coms from a place that's called "ruby".
It seems MacOS uses some gems and code from ruby itself, but in the last catalina update, apple seems to have locked that installation down "because security".
A big help was this article, Have you seen it / tried it?
From it I now understand that we'd need to start our own directory and ruby gem install system instead of just installing to apple's internal OS directory as pre-catalina...
I'm quite busy so maybe have a look at that site and see if you can get something. If not I'll try look into it further, though I'm afraid that my ruby installation would look, if it was in the physical form, like a hacked together patchy mess!