I am sorry @ard_dev, I should have read your original question more carefully. My focus was on getting aliases configured and this is how I do it via config.inc.php. See https://docs.phpmyadmin.net/en/latest/config.html#cfg_Servers_verbose
WRT phpmyadmin.conf, I am unable to find that file on the phpmyadmin which I have installed via Virtualmin’s Install Script feature on a Debian 9 system. Sorry about the confusion.