Hello ; I think that the "hole" settings allow only to draw a circular hole. You still can do what you are requesting other way : Just after you finish the making of your board outline shape you use the board outline layer "see the next image" to draw a rectangle (or whatever shape you want) in the middle of your board  After drawing the shape, it will be then produced as a shaft in your circuit. see the images below  This is the photo view on how it will look like the PCB after producing it.  And yes, JLCPCB support the requested dimensions.

@Rumail Memon, @JLCPCBsupport, You can also use the **Solid Region** Tool set to **Board Cutout**.  I think the minimum corner radius may be 0.15mm. I asked support about this a couple of years ago but can't find the post so I'm not sure if I got an answer. :)

@JLCPCBsupport What tool to use to create the inner rectangle?

@rm4631 Just draw it with the track tool, and it should be fine as long as you are selecting board outline from the layers palette. :)