How do I update software on Mojave to my iMac

Choose Mojave or Catalina from this list: How to get old versions of macOS - Apple Support. Backup before installing.

If your iMac is 2014 or newer, go to the Mac App Store and search for "macOS Big Sur". Backup before installing.

Cheers,

Jack

Hi Hoza1,

This is not a live chat. You will not receive responses immediately.

Please go to the Apple menu (top left) > About this Mac, and post the year of your Mac, such as "Late 2015".

Cheers,

Jack