Issue Custom theme designer

[capps]

Server operating system version

Alma Linux 9

Plesk version and microupdate number

Plesk Obsidian 18.0.70.2 (Pro)

I am trying to edit my theme on Plesk Obsidian. I followed the following instructies.

Obtaining a Theme Package from Plesk

To obtain the files needed for creating a custom theme, connect to the server through SSH (on Linux) or a Remote Desk...

docs.plesk.com

When I unzip the file I get the following messages..

warning: stripped absolute path spec from /images/logos/plesk/logo-web-host.png
inflating: theme/images/logos/plesk/logo-web-host.png
warning: stripped absolute path spec from /images/logos/plesk/logo-web-pro.png
inflating: theme/images/logos/plesk/logo-web-pro.png
warning: stripped absolute path spec from /images/logos/plesk/logo.svg
inflating: theme/images/logos/plesk/logo.svg
warning: stripped absolute path spec from /images/sitejet-dialog/banner.png
inflating: theme/images/sitejet-dialog/banner.png
warning: stripped absolute path spec from /images/sitejet-dialog/screenshots/1.png
inflating: theme/images/sitejet-dialog/screenshots/1.png
warning: stripped absolute path spec from /images/sitejet-dialog/screenshots/2.png
inflating: theme/images/sitejet-dialog/screenshots/2.png
warning: stripped absolute path spec from /images/sitejet-dialog/screenshots/3.png
inflating: theme/images/sitejet-dialog/screenshots/3.png
warning: stripped absolute path spec from /meta.xml
inflating: theme/meta.xml
warning: stripped absolute path spec from /css/custom.css
extracting: theme/css/custom.css

The files are created but the css file theme/css/custom.css for example is empty.

Is this normal and where do I go from here?