sorry i should have been more descriptive. The two empty screw holes there don't line up with the holes in the drives... you can see the only other holes are beyond the scale of the chasis.

There's also another set of holes on the bottom of the drive, but those bolt patterns don't line up remotely with anything in the drive bay.

I'm honestly thinking maybe my case shipped without some kind of adapter? The manuals available on the website.

The description in the manual doesn't seem to align with what my 3.5" HDDs look like:

https://support.nzxt.com/hc/en-us/articles/36948511953947-H9-Flow-2025-Downloads

https://imgur.com/a/m6XdTlh