I am unable to upgrade my Mac OS from Mohave to Ventura because my HD "s not formatted for APFS". How do I fix this so I can upgrade?

Before doing anything else, make sure to have a good backup in case something goes wrong.

You an try converting the file system to APFS by booting into Recovery Mode (Command + R). Launch Disk Utility and click on "Macintosh HD" on the left pane of Disk Utility (or click on the current name if you customized it). Right-click or Control-click on "Macintosh HD" and select "Convert to APFS" on the resulting pop-up menu. Theoretically this should not destroy your current macOS installation or data, but this is a major undertaking so make sure to have a good backup first just to be safe.

Hi there!

I have a free questions I'd like to ask:

1. What version of macOS Mojave are you using (e.g. 10.14.6)? To find out, go to the Apple menu  > About This Mac.
2. What model and year is your Mac? This can also be found from About This Mac.

Also, do you have a backup of your Mac?

Let us know!

Jack