The latest version of Capture One 22 (15.4.1) now supports Nikon Z9 compressed files (HE* & HE) – the release notes can be found here.
Previously, the new ON1 Photo RAW 2023 was the only software with support for Nikon Z9 HE RAW format files.
Capture On2 22 (already on closeout) will soon be replaced by version 23. The German retailer Foto Erhardt recently had a promoti0on where you could buy Capture One Pro version 22, and get the not-yet-released version 23 for free. Exactly around the same time last year, Capture One had a similar promotion and two months later (in December) the new Capture One version was officially announced.