Happy New Year everyone.
I am now an owner of an Acer A515-51G laptop and I'm trying to install SL 7.4 in EFI mode dual boot with Win 10.
After lots of experiments I was only able to install in legacy mode, but that locked me out of Win 10.
I am trying to run mokutil, but I get an error as follows:
mokutil --import /etc/pki/secure-boot/SECURE-BOOT-KEY-fnal-sl7-exp-2020-08-26
EFI variables are not supported on this system
Elsewhere, it was suggested to do modprobe efivars, but efivars does not appear to be available.
Any suggestions as to what to do next?

Cheers
Bill Maidment