apple id issue on older mac pro’s

my 86 yr old mother cant use her apple id on her mac pro. “it can only be used o devices macOS 13.1 or later’ and her mac pro cannot be updated it currently runs macOS Monterey v 12.7.6. is there any work around for this? she is not buying another laptop at her age, and has enough stuff on her account that she pays apple for extra storage. i am leaving the country in 2 days so a bit urgent. thx