@Juan,

You can install PhpMyAdmin on Debian 10 using the following commands.

$ wget https://files.phpmyadmin.net/phpMyAdmin/5.0.2/phpMyAdmin-5.0.2-all-languages.zip
$ tar xvf phpMyAdmin-5.0.2-all-languages.zip
$ sudo mv phpMyAdmin-*/ /usr/share/phpmyadmin
$ sudo mkdir -p /var/lib/phpmyadmin/tmp
$ sudo chown -R www-data:www-data /var/lib/phpmyadmin
$ sudo mkdir /etc/phpmyadmin/
$ sudo cp /usr/share/phpmyadmin/config.sample.inc.php  /usr/share/phpmyadmin/config.inc.php

Open the configuration config.inc.php file, set secret passphrase and tmp directory.

$cfg['blowfish_secret'] = 'H2OxcGXxflSd8JwrwVlh6KW6s2rER63i'; 
$cfg['TempDir'] = '/var/lib/phpmyadmin/tmp';

Configure your apache to access the phpmyadmin.

How do I fix the hostname error?

Kind regards Niklas