Big Sur upgrade from Mojave
I have iMacPro 2017 and I want to upgrade to Big Sur. I can not launch the Big Sur update from App store. If I click on 'Get' in App Store, It directs me to System preferences/Software update box, and I have a message: "Update not found. The requested version of macOS is not available."
I can not update to Monterey, the softwares what I use doesn't support it yet.
iMac Pro