Yes, I think you need to deploy the files yourself. I think grub2-efi rpm contains the efi files.
Quoting the information from obsolete foreman-bootloaders repository
Foreman installer now generates grub2 image via grub2-mknetdir command and it is possible to do this on Red Hat systems for multiple architectures. Other bootloaders like grub1 or pxelinux must be acquired from upstream projects.
It’s weird this is not documented anywhere but I didn’t find any code that would do that for the user. @lzap do you happen to know?
I already deployed the files myself and verified the selinux . Aftrer that, when generate the Host Image, I obtained the following error:
Oops, we're sorry but something went wrong ERF42-8203 [Foreman::Exception]: Ensure /var/lib/foreman/bootdisk/shimx64.efi is readable (or update "Grub2 directory" setting)
Lastly, I searched for shimx64.efi on the machine and find the file at /boot/efi/EFI/redhat/. I copied the file to /var/lib/foreman/bootdisk/ and now I’m able to generate Host Images.
NOTE:grubx64.efi is also in the same folder as shimx64.efi (/boot/efi/EFI/redhat/). You can also copy this file to /var/lib/foreman/bootdisk/.