/etc/apt/sources.list.d/ error code example
Example: /etc/apt/sources.list not found
Some of the solutions that will help for solving this issue :=
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1. https://stackoverflow.com/questions/5231160/sudo-apt-get-command-not-found
2. https://www.psychz.net/client/question/en/apt-get-command-not-found.html#:~:text=If%20the%20command%20returns%20no,%2Fetc%2Fapt%2Fsources.&text=In%20the%20mirror%2C%20go%20to,file%20suitable%20for%20your%20architecture.
3. https://askubuntu.com/questions/538676/etc-apt-sources-list-not-found