OpenVPN Keys

I am having trouble generating keys using the instructions at;

https://github.com/RMerl/asuswrt-mer...using-Easy-RSA

I can create the easy-rsa directory using the setuprsa.sh script but cannot get into the directory using the Run System Command.

mnt/sda1/easy-rsa/: Permission denied

I can edit the vars file in the directory in windows.

Any thoughts?

Thanks