when i hold option and select the usb, it doesn’t work. it says software update then software update not possible. It works with my old mac (MacBook Air 13" 2015) but not with this one (MacBook Pro 13" 2020 )
MacBook Pro 13″, macOS 10.15
You need to boot into Recovery Mode and use the security utility located on the "Utilities" menu to "allow booting from USB". Then you can reboot to the USB drive. If you are booting a non-Apple OS, then you also need to uncheck "No Security".
Is your Mac connected to the network as it needs Internet access to confirm the drive and permissions. While I appreciate having extra security like this I really hate how Apple has implemented this feature. It is awkward for no reason and there are gaps in the security model anyway which makes this process even more frustrating to the way it has been implemented.
Otherwise you need to contact Apple Support directly for assistance by clicking the "Get Support" link at the top right of this page.
It didn't work. they were already on. these are the errors
It is connected to a network. thanks for your help.
Boot from usb
