I have changed it in both /etc/postgres, /etc/postgres16, /var/lib/postgresql16/data/postgresql.conf and /var/lib/postgresql/data/postgresql.conf and it still showing the same error. Am I missing something here?

Hi Miklós, I can not be more agree on that too. The goal of the article was to guide those who are just following tutorials here and there and keep doing that like an infinite loop without moving anywhere further.