$HOME.rm "~/Desktop/$filename"rm "$HOME/Desktop/$filename"Tilde does not expand to the user's home directory when it's single
or double quoted. Use double quotes and $HOME instead.
Alternatively, the ~/ can be left unquoted, as in
rm ~/"Desktop/$filename".
If you don't want the tilde to be expanded, you can ignore this message.
ShellCheck is a static analysis tool for shell scripts. This page is part of its documentation.