luci/applications/luci-app-yggdrasil/root/usr/share/rpcd/acl.d/luci-app-yggdrasil.json

{
        "luci-app-yggdrasil": {
                "description": "Grant access to LuCI app yggdrasil",
                "write": {
                        "file": {
                                "/usr/sbin/yggdrasilctl": [ "exec" ]
                        }
                }
        }
}