slot holes - PCB Panelization - jlcpcb.com samurai 888 katsumi slot machine

Hi, so far I used regular rounded holes but I need to make 3mm wide square holes and I was wondering if it was possible with Kicad also is JLCPCB (or other manufacturers) accept these sorts of cut-outs thanks for your help.

I'm trying to create PCB footprints for some parts that use an oval shape slot hole for snap-in mounting.The standard pad menu only seems to offer circular holes.

Nickels (No Dates) (GX51B) Nickels 25 slot(s). White. This holder has 25 holes without dates with a snap style. The size is 6.5x6.5.