This question already has an answer here:

I have a 4k display, so by default Spotify is incredibly zoomed out. To fix this, I had a look at this post, which recommends adding a command line option. This works when I launch Spotify through the terminal, however I want it to launch that way by default when I click on the icon. I attemped to follow the guidance in the rest of the solution, which mentions editing spotify.desktop, however whenever I try to edit it gedit says the file is read-only, even using sudo. First, I used sudo find . -name spotify.desktop and got the response of:

find: ‘./run/user/1000/gvfs’: Permission denied
find: ‘./proc/19908/task/19908/net’: Invalid argument
find: ‘./proc/19908/net’: Invalid argument

Running sudo gedit /snap/spotify/21/meta/gui/spotify.desktop or sudo gedit /snap/spotify/21/usr/share/spotify/spotify.desktop opens gedit, but in read-only mode. Attempts to change the file permissions leads to chmod: changing permissions of '/snap/spotify/21/usr/share/spotify/': Read-only file system.

How should I best proceed?

marked as duplicate by pomsky, Zanna, karel, muru command-line Oct 28 '18 at 5:40

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.