coc-settings.json

{
        "explorer.icon.enableNerdfont": true, 
        "diagnostic-languageserver.filetypes": {
                // lint `sh` (includes `bash`) files
                "sh": "shellcheck"
        },
        "diagnostic-languageserver.formatFiletypes": {
                "sh": "shfmt"
        },
        "diagnostic-languageserver.formatters": {
                // define our formatter so that we can reference it from
                // `diagnostic-languageserver.formatFiletypes`
                "shfmt": {
                        "command": "shfmt",
                        // all the below args are entirely optional
                        // primarily listed here to call out that flags which take an
                        // argument (such as `-i <num-spaces>` for specifying indentation)
                        // should be split into two strings, the flag and then the value
                        "args": [
                                "-i",
                                "4"
                        ]
                }
        }
}