1.) Prepare your system

sudo apt update
sudo apt install lsb-release apt-transport-https bzip2 ca-certificates curl

2.) Choose stability

curl -sSLo /tmp/multiflexi-archive-keyring.deb https://repo.multiflexi.eu/multiflexi-archive-keyring.deb
dpkg -i /tmp/multiflexi-archive-keyring.deb
sh -c 'echo "deb [signed-by=/usr/share/keyrings/repo.multiflexi.eu.gpg] https://repo.multiflexi.eu/ $(lsb_release -sc) main" > /etc/apt/sources.list.d/multiflexi.list'
wget -qO- https://repo.vitexsoftware.com/keyring.gpg | sudo tee /etc/apt/trusted.gpg.d/vitexsoftware.gpg
echo "deb [signed-by=/etc/apt/trusted.gpg.d/vitexsoftware.gpg]  https://repo.vitexsoftware.com  $(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/vitexsoftware.list

3.) Update Sources

sudo apt update

4.) Install for chosen database

sudo apt install multiflexi-mysql
sudo apt install multiflexi-pgsql
sudo apt install multiflexi-sqlite

5.) Check for applications Availble

apt search multiflexi