https://github.com/xzilla/phppgadmin - git-репозитарий
https://github.com/phppgadmin/phppgadmin/releases

в файле congif.inc.php настроить параметры, особенно $conf['servers'][0]['host'] = 'localhost';

/etc/apache2/conf-available/phppgadmin.conf

<Directory /usr/share/phppgadmin>
....
Require all granted
....
</Directory>

/etc/apache2/conf-available/phppgadmin.conf

Alias /phppgadmin /var/www/phppgadmin
<Directory /var/www/phppgadmin>
  Require all granted
 
  <IfModule mod_dir.c>
    DirectoryIndex index.php
  </IfModule>
 
  AllowOverride None
 
  # Only allow connections from localhost:
  #Require local
 
  <IfModule mod_php.c>
    php_flag magic_quotes_gpc Off
    php_flag track_vars On
    #php_value include_path .
  </IfModule>
 
  <IfModule !mod_php.c>
    <IfModule mod_actions.c>
      <IfModule mod_cgi.c>
        AddType application/x-httpd-php .php
        Action application/x-httpd-php /cgi-bin/php
      </IfModule>
      <IfModule mod_cgid.c>
        AddType application/x-httpd-php .php
        Action application/x-httpd-php /cgi-bin/php
      </IfModule>
    </IfModule>
  </IfModule>
</Directory>