How To Install VIrtualmin

Update your Debian server
Check everything is up to date
Log onto your server and first update/upgrade it with the following commands:

sudo apt update
sudo apt upgrade

Install Webmin and Virtualmin
Download Virtualmin using the below script. It is basically a shell script that will handle rest of the installation once executed.
Then run it

curl -o install-virtualmin.sh https://gitlab.com/wikisuite/virtualmin-installer/-/raw/master/install-virtualmin.sh
bash install-virtualmin.sh

first install all dependenices

apt-get update
apt-get upgrade
sudo apt install php php-tidy php-pear php-gd php-xmlrpc php-mbstring libapache2-mod-php php-mysql php-apcu php-curl php-intl php-sqlite3 php-zip php-memcache php-pspell php-zip php-memcached php-pear php-common php-intl php7.4-opcache php-xml php-zip composer php-bz2 git unzip sqlite3 php php-pdo rsync composer curl memcached poppler-utils bsdmainutils catdoc elinks man-db odt2txt pstotext unzip apache2 mysql-server mysql-client
apt install php-bz2

installation of tiki-manager and composer

1. clone directory

git clone depth 1 branch master https://gitlab.com/tikiwiki/tiki-manager.git

1. go to this directory

cd tiki-manager

1. install composer

curl https://getcomposer.org/composer.phar > composer.phar
php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
php -r "if (hash_file('sha384', 'composer-setup.php') === 'c31c1e292ad7be5f49291169c0ac8f683499edddcfd4e42232982d0fd193004208a58ff6f353fde0012d35fdd72bc394') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"
composer require symfony/finder
composer require symfony/console