Thank you, guys.
I installed TwentyTwentyFour and edited the main menu template. It works so far, but I could not manage to make it work by entering a relative URL like /#someSecion
. I had to enter the full URL, which seems weird. I guess a CMS/blog system that is out there since ages and that actually has the capacity to define anchors for content elements might have a way to reference them without throwing the absolute URL into the database. Am I doing something wrong?