I'm trying "How To Install and Secure phpMyAdmin with Apache on a CentOS 7 Server" but the file /etc/httpd/conf.d/phpMyAdmin.conf is empty so there is nothing to edit or replace. It is completely empty. I ran sudo nano /etc/httpd/conf.d/phpMyAdmin.conf as instructed by the KB:

https://www.digitalocean.com/community/tutorials/how-to-install-and-secure-phpmyadmin-with-apache-on-a-centos-7-server