I'm applying this to multiple nodes. These are normal Basic Pages, I didn't add programming to the way they are aquired, so I assume the standard Drupal logic for displaying content is used. I only changed page.html.twig, which only contains {{ content }} in a div, said simply.

sorry for the basic question... but how do I get the node ID?

mytheme, I corrected it.

No difference. I also added an edit to the bottom of my description of the problem.