Copy a file from system to chroot directory

First check where the chroot directory is mounted(let’s assume /mnt)

after chrooting inside mnt(chroot /mnt)

open another terminal and type in

sudo cp /etc/resolv.conf /mnt/etc

I’ve booted into a live cd, mounted the root partition on /mnt and chrooted.So, I’m copying resolv.conf from the systems etc directoy to the chrooted etc.