This is for a Linux only install, no dual-boot with Windows

When first booting up the AIO hit the Esc key then enter “System Settings”
Change “Secure Boot Configuration” to:

Legacy Support Disable
Secure Boot Enable
Key Management Clear
Key Ownership Custom keys
Fast Boot Disable

F10 to save, then choose DVD from boot menu, start the install as normal.

When asked for modules to load during install choose “mbr-udeb” & “parted-udeb”, and what ever other modules you need.
Choose manual hard drive configuration, set “/dev/sda1” to 1GB as “EFI Boot Sector”.
Then partition the rest as needed.
Install grub to “/dev/sda1”, and finish the install.