Hi,
If you upgraded by the script, the phpmyadmin url will become phpmyadmin, e.g. www.example.com/phpmyadmin/, this part is hard coded for now.
To change it, edit /usr/local/lsws/conf/httpd.conf, and change
Alias /phpmyadmin/ /var/www/phpmyadmin/
to
Alias /custom-url/ /var/www/phpmyadmin/...