I have macOS El Capitan on my Mac Pro and I am trying to update my Mac Pro to macOS High Sierra so I can update it to Mojave later since Mojave requires to have at least macOS High Sierra. But when I run the installer I get the below error. Any advice on the steps needed to overcome this issue?
This is my Mac Pro specs:
This is my disks in Disk utility:
This is my Mac Pro specs:
This is my disks in Disk utility: