How to add plonetheme.barceloneta to plone 6 Classic?

I am new to Plone 6, so maybe it's a dumb question.

I follow the doc over the net to install Plone 6 and after that I got a broken site, no theme / css etc.

How can I add plonetheme.barceloneta?

I used to be using buildout for plone install. So I have no idea. Can someone point my out.

Many thanks.

I place a dumb question as well, did you create the site clicking the "Create Classic Plone site" button?

Perhaps you are on, thats per default unstyled. You can disable this "no-style mode" in the configuration panel. configuration -> design -> Remove the host entry under "hostname without design"

Thanks for all reply I have find the way to do it