What model of Mac are you runnung Fusion 13 on?
If it’s an M1 or M2 Mac, you can’t run any version of macOS under Fusion. Parallels ($$$) and UTM (free) will enable you to run Monterey and later versions only.
If it’s an Intel Mac, and you have a .dmg file containing the installer
- open the .dmg file
- Double click on the installer package to install the installation app into /Applications
- create a new virtual machine in Fusion
- drag and drop the installer app found in the /Applications folder onto the Create a new virtual machine dialog
- Paul (Technogeezer)
Editor of the Unofficial Fusion Companion Guides
