Using qpdfview with AUCTeX

I recently set up a new computer using Debian Buster with LXQt as desktop environment, which uses qpdfview as default PDF viewer. Obviously I wanted to make use of it when writing LaTeX documents in Emacs using AUCTeX. Mathieu Morey once wrote an explanation how to configure an alternative PDF viewer, which is nowadays archived. However, this explanation uses Emacs’ inbuilt configuration buffers, while I prefer adding simple Emacs Lisp to the initialisation file.