Editing sources.list On kali code is in description
# deb cdrom:[Kali GNU/Linux 2020.1b Kali-last-snapshot - Official amd64 DVD Binary-1 with firmware 20200316-17:52]/ kali-rolling contrib main non-free
#deb cdrom:[Kali GNU/Linux 2020.1b Kali-last-snapshot - Official amd64 DVD Binary-1 with firmware 20200316-17:52]/ kali-rolling contrib main non-free
This system was installed using small removable media
(e.g. netinst, live or single CD). The matching "deb cdrom"
entries were disabled at the end of the installation process.
For information about how to configure apt package sources,
see the sources.list(5) manual.
deb http://http.kali.org/kali kali-rolling main non-free contrib
deb-src http://http.kali.org/kali kali-rolling main non-free contrib
*****note that image of thumbnil isn't mine
credit goes to it's developer or who's the owner