So, please don’t laugh about this question. I read about Kirby in ct’ and I sucessfully installed Kirby on my webspace. That is not too easy for someone, who is used to install Wordpress with one mouseclick;-)
I read about installing the plugin “Webmentions” There I found: “Additionally you have to specify your new webmention endpoint in the header of your site”.
My question: what file contains the header?
Would be glad to make further steps with Kirby. Thanks for your answers.