Repairing a creaky chair

[Toliy]

I often work from home and have a very beautiful chair.
However, it now makes a squeaking sound whenever I sit on it or move slightly, which is very annoying.
But replacing it with a new chair would be very expensive.

So in my mind, you figure out what is creaking and go from there! It could be a simple as tightening something up or getting out rhe classic WD40!