Для краткости чисто команды для ввода на сервере без комментариев.
Сервер l2jmobius. в коде встречается установка или C6_Interlude или CT_2.6_HighFive выбрать можно и другой из доступных

sudo apt update
sudo apt upgrade
sudo apt install git
sudo apt-get install software-properties-common
sudo add-apt-repository ppa:linuxuprising/java -y
sudo apt-get install oracle-java17-installer oracle-java17-set-default
java --version
sudo apt-get install ant
git clone https://bitbucket.org/MobiusDev/l2j_mobius.git
cd l2j_mobius/L2J_Mobius_CT_2.6_HighFive
---- cd l2j_mobius/L2J_Mobius_C6_Interlude
ant
sudo apt install mariadb-server mariadb-client
service mysqld status
mysql_secure_installation
mysql -u root -p
CREATE DATABASE IF NOT EXISTS l2jmobius CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;
GRANT ALL PRIVILEGES ON l2jmobius.* TO 'root'@'localhost';
CREATE USER IF NOT EXISTS 'l2jmobius'@'localhost' IDENTIFIED BY '123456789';
GRANT ALL PRIVILEGES ON l2jmobius.* TO 'l2jmobius'@'localhost';
FLUSH PRIVILEGES;
exit
cd /root/l2j_mobius/build
mkdir /opt/Server
mv L2J_Mobius_CT_2.6_HighFive.zip /opt/Server/
---- mv L2J_Mobius_C6_Interlude.zip /opt/Server/
cd /opt/Server
sudo apt install unzip
sudo apt install p7zip
---- unzip L2J_Mobius_C6_Interlude.zip
unzip L2J_Mobius_CT_2.6_HighFive.zip
cd db_installer
java -jar Database_Installer_LS.jar
java -jar Database_Installer_GS.jar
cd /opt/Server/login/config
nano LoginServer.ini
cd ..
chmod +x RegisterGameServer.sh
./RegisterGameServer.sh
mv hexid.txt /opt/Server/game/config/
cd /opt/Server/game/config
nano Server.ini
cd /opt/Server/login
chmod +x LoginServer.sh
chmod +x LoginServerTask.sh
mkdir log
cd log
tail -f stdout.log
sudo apt-get install htop
htop
cd /opt/Server/game
mkdir log
chmod +x GameServer.sh
chmod +x GameServerTask.sh
./GameServer.sh
cd log
tail -f stdout.log