Can I put gel stain directly over top paint?

Probably not. It can ruin the paint finish and possibly take forever to dry.

https://www.pinterest.com/pin/228346643582055090/

yes you can! :-)

be sure to do a test board and/or seal it first so you have more control.

Yes you can. You may want to add a layer of topcoat first though to make the stain easier to work with and give you more ability to move it around to get the look you want. Chalk paint may just absorb it too fast.

Absolutely you can ! You will just need more coats. Probably at least 4 coats of gel stain.

https://letspaintfurniture.com/how-to-use-gel-stain/