I tried to install spotify with a repo but I think I did something wrong. Ever since I did this I can't fetch updates in the App enter- Failed to fetch updates : How to fix corrupt source file Details :E: Type ‘sudo’ is not known on line 1 in source list /etc/apt/sources.list.d/spotify.list E: The list of sources could not be read
Simply removing the file should solve your issue.
In Terminal run:
sudo rm /etc/apt/sources.list.d/spotify.list
I suggest installing it from Flathub. Click on the blue 'Install' button and the click the downloaded file.