You mean a PDW kit? Most people associate pistol carbines with stuff like the Urutau or DB9 or stuff like that, not with chassis for handguns. PDW is the tearm most people use for what you're looking for.

Anyway, I've never made one, but the Super Patriot has STEP files, so you could remix it for a Hellcat slide as long as you've got the measurements right. https://guncadindex.com/detail/Super-Patriot-PDW-Blank-Series:e

Search guncadindex for "PDW chassis" and you'll find several Glock options (e.g. https://guncadindex.com/detail/glock-pdw-chassis:1). Not likely to find much for the Hellcat since they have such a small market share compared to Glock.

DB9 Alloy Lage edition, FGC-9, SL-9 or search unseenkiller on the Index

there is not one for the hellcat. Danish bulldog just made a printed frame for the hellcat. If you've never printed before then stick to the commercial space. there is not going to be a hellcat frame for a long time.