sing-box/release/config/sing-box.rules

polkit.addRule(function(action, subject) {
    if ((action.id == "org.freedesktop.resolve1.set-domains" ||
         action.id == "org.freedesktop.resolve1.set-default-route" ||
         action.id == "org.freedesktop.resolve1.set-dns-servers") &&
        subject.user == "sing-box") {
        return polkit.Result.YES;
    }
});