hello, I just finish to install on VMware "The Perfect Server - Ubuntu 20.04 with Apache..." and I'm trying to install somes old PHP version such as 5.6/ 7.0 / 7.2. Last time with Ubuntu 18.04 I used this tutorial "How to install PHP 5.6 and 7.0 - 7.4 as PHP-FPM & FastCGI for ISPConfig 3.1 with apt on Debian 8 to 10" (Cannot find one for ISPConfig / Ubuntu). But this time it doesn't work. Package php5.6-json is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source I get the same message for PHP 7.0 / 7.1 / 7.2 / 7.3. How can I install old PHP versions ?