openwrt-packages/luci-app-design-config/root/usr/share/rpcd/acl.d/luci-app-design-config.json

{
    "luci-app-design-config": {
        "description": "Grant UCI access for luci-app-design-config",
        "read": {
            "uci": [ "design" ]
        },
        "write": {
            "uci": [ "design" ]
        }
    }
}