Mojave to Big Sur Upgrade
When I try to Upgrade from Mojave to Big Sur I get , "Update not found. The requested version of Mac OS is not available". I'm currently running Mojave 10.14.6 on a mid 2012 Mac Pro Desktop with updated 'metal' graphics Radeon RX580.
Any suggestions on how to Up grade (not up date).
Mac Pro, macOS 10.14