File Name ↓	File Size ↓	Date ↓
Parent directory/	-	-
ce-phoenix-admin_1.0.7.13_all.deb	185.2 KiB	2021-Jan-14 16:30
ce-phoenix-installer_1.0.7.13_all.deb	59.4 KiB	2021-Jan-14 16:30
ce-phoenix-installer_1.0.7.3_all.deb	69.0 KiB	2020-Aug-01 18:04
ce-phoenix_1.0.7.13_all.deb	955.3 KiB	2021-Jan-14 16:30
ce-phoenix_1.0.7.3_all.deb	886.7 KiB	2020-Aug-01 18:04

Please copy & paste to your terminal:

	    
sudo apt install lsb-release wget apt-transport-https bzip2

sudo wget -O /usr/share/keyrings/vitexsoftware.gpg https://repo.vitexsoftware.cz/keyring.gpg
echo "deb [signed-by=/usr/share/keyrings/vitexsoftware.gpg]  https://repo.vitexsoftware.cz  $(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/vitexsoftware.list
sudo apt update

sudo apt install package(s)

You can also add backports after main if you want install newer versions of software already present in debian.

VitexSoftware's package repository

How to use repository ?