I have created one new user according to this link "https://wiki.openwrt.org/doc/howto/secure.access" and followed the Method 2. I want to switch from root to new user in OpenWrt as I did in Ubuntu in Ubuntu using 'su -l dhaka(username)' to switch from rafsan to dhaka user. But the OpenWrt prompts "'su' is not found" .
In order to use su, the shadow package needs to be installed.
opkg install shadow