Can’t find css/admin_bar.css to copy it into child theme?

Hi,

I activated this plugin. I have already edited the current parent theme, but just in the content no code. I got this message while creating its child theme:
“this theme loads after style.css css/admin_bar.css consider saving new custom styles to a separate stylesheet (step 5 below) so you can customize these styles”

how to do this exactly? so far i have never created a child theme. should i click on separate stylesheet and it will include both style.css and admin_bar.css? I want to make sure i don’t lack anything when i create the child theme i will be working on but that copies the current parent theme i am using

I went wp-admin then opened css folder but i can’t find this admin_bar.css. where is it? or maybe is it called in another way?
also would this admin_bar be responsible for the top bar menu of my website or other menus or there is no link and can just create style.css file