Writable (public download method) The directory ../private does not exist.

I followed the steps

composer create-project -s dev centarro/commerce-kickstart-project kickstart
cd kickstart
composer require drupal/commerce_demo:^3.0

Now I have the

Writable (public download method)
The directory ../private does not exist. An automated attempt to create this directory failed, possibly due to a permissions problem. To proceed with the installation, either create the directory and modify its permissions manually or ensure that the installer has the permissions to create it automatically. For more information, see INSTALL.txt or the online handbook.

What does it mean? Where do I create this folder? ../ this path is related to what? domain?
should i create it near vendor or in sites/default/files direcory???