PHP Extensions
PHP Extensions (/php/extensions) lists the extensions each installed PHP
version has, and their state: active, disabled, or not installed. You can enable
or disable an extension, and install one that is not there yet — installs run in
the background and the page polls for the result. PHP-FPM is restarted
afterwards.
Installing and removing PHP versions
On a Community server this page is also where whole PHP versions are added and removed. Community has no admin panel — port 2087 is closed — so the person running the server signs in here, and this is the only place the machine's PHP versions can be managed from.
On Enterprise the people signed in here are hosting customers and this control is not offered: a PHP version is shared by every account on the machine, so removing one takes it from the neighbours. It moves to the admin panel, which on that edition exists. See PHP Settings on the admin side.
What may be removed is not decided by the page. hitechcloudcli phpversions remove refuses a version any website still runs on, and refuses the default for
new sites, and it names the websites in its refusal. The page shows what each
version is carrying before you click, instead of offering a button that would
be refused.
A default install brings up eight versions — 5.6, 7.4 and 8.1 through 8.6 — because every installed version runs a process manager and its idle workers from boot whether or not a website uses it. The rest are a minute away when somebody needs one.