We have a new SP 2019 server farm set up and I was investigating the Communication site template. By default, a new communication site starts with the Topic template assigned. Looking at https://support.office.com/client/results?ns=WSSENDUSER&version=19&helpId=WSSEndUser_CommSiteNewsEmptyStateTile_WhatIsACommunicationSite&shownav=true&web=1 I should be able to change to either the Showcase or Blank template, but I can't find the actual control for that anywhere. First issue is the instruction to select "Settings" then "Site templates". Of course there isn't anything labeled Settings on the page and the "gear" menu only has Add a page; Add an app; Site contents; Site information; Site permissions; and Change the look. If I go to Site information, then View all site settings, there isn't anything in the site settings page for changing the template either. I've even tried looking at SPO to get the URL there for changing the template and seeing if I could hack the URL on SP 2019 to get there, but that page doesn't exist in the on-prem install.
So either I'm just missing where it is in the on-prem install or it doesn't exist in the on-prem install (in spite of all the documentation I've seen). If anyone can give me some insight, I'd really appreciate it. Thanks.