Enabling gzip compression for webserver from Plesk interface
Ability to configure gzip compression server wide from Plesk GUI
You can do it in Plesk GUI in Additional directives – https://support.plesk.com/hc/en-us/articles/115002058474-How-to-enable-gzip-compression-for-a-website-on-Linux
@Plesk Staff: No, it isn't. Least no longer in the latest Plesk version. Would be nice to see outdated stuff deleted. It's a waste of time reading through thousands of rubbish content Google is so happy about to hold onto.
That's a No-Brainer, isn't it!
Can't believe that they have a "Calculate size" button but no compress files button
As for server-wide configuration, it is not possible to do it from Plesk GUI