@SYS/persistent.parm sysfs file using a mavftp client

Good evening, I am trying to look at the persistent.parm sysfs file by downloading it using MAVproxy. Module ftp
However, I can only assume this file is within the APM directory but I don’t know how to either, open the directors using MAVProxy or download the entire directory using ‘get’.
If I try ftp get APM I just get a response of : - ftp open failed.

Any advice would be very grateful.
Thanks