I followed the instructions there with the result: The panel cannot connect to the API
I created /site/config/config.php and added the panel enabling code – but initially without <?php and ?> because the code in the docs does not contain those, unless I missed it.
Adding those to /site/config/config.php now reveals the panel. Thank you! My next task will be to implement the site I created in localhost, on the public server.
Yes that is why I chose Kirby after trying umpteen flat-file CMS and dealing with their poor documentation, super complex default demo sites, uncommented templates and etc. Kirby looked to me to have the best combination of things and the docs are in competent English (unlike my incompetent German).