this should work (for Debian 12):
1) adding deb.sury.org repo
Code:
curl -sSLo /tmp/debsuryorg-archive-keyring.deb https://packages.sury.org/debsuryorg-archive-keyring.deb
dpkg -i /tmp/debsuryorg-archive-keyring.deb
sh -c 'echo "deb [signed-by=/usr/share/keyrings/deb.sury.org-php.gpg] https://packages.sury.org/php/ $(lsb_release -sc) main" > /etc/apt/sources.list.d/php.list'
2) installing PHP 5.6 (FPM)
Code:
apt update
apt install php5.6-fpm
3) registering PHP 5.6 (FPM) in Plesk
Code:
plesk bin php_handler --add -displayname 5.6.40 -path /usr/sbin/php-fpm5.6 -phpini /etc/php/5.6/fpm/php.ini -type fpm -id deb-php56-fpm -clipath /usr/bin/php5.6 -service php5.6-fpm -poold /etc/php/5.6/fpm/pool.d