Saving the G+ Delphi Developers community on your site gives an error

[jpluimers]

Trying to save https://plus.google.com/communities/103113685381486591754, using https://wispsoftime.com/gplus-archiver/archive/103113685381486591754 gives this error:

Slim Application Error
The application could not run because of the following error:

Details
Type: Error
Message: Class 'ZipArchive' not found
File: /var/www/gplus-archiver/public/index.php
Line: 258
Trace
#0 [internal function]: Closure->{closure}(Object(Slim\Http\Request), Object(Slim\Http\Response), Array)
#1 /var/www/gplus-archiver/vendor/slim/slim/Slim/Handlers/Strategies/RequestResponse.php(41): call_user_func(Object(Closure), Object(Slim\Http\Request), Object(Slim\Http\Response), Array)
#2 /var/www/gplus-archiver/vendor/slim/slim/Slim/Route.php(356): Slim\Handlers\Strategies\RequestResponse->__invoke(Object(Closure), Object(Slim\Http\Request), Object(Slim\Http\Response), Array)
#3 /var/www/gplus-archiver/vendor/slim/slim/Slim/MiddlewareAwareTrait.php(117): Slim\Route->__invoke(Object(Slim\Http\Request), Object(Slim\Http\Response))
#4 /var/www/gplus-archiver/vendor/slim/slim/Slim/Route.php(334): Slim\Route->callMiddlewareStack(Object(Slim\Http\Request), Object(Slim\Http\Response))
#5 /var/www/gplus-archiver/vendor/slim/slim/Slim/App.php(515): Slim\Route->run(Object(Slim\Http\Request), Object(Slim\Http\Response))
#6 /var/www/gplus-archiver/vendor/slim/slim/Slim/MiddlewareAwareTrait.php(117): Slim\App->__invoke(Object(Slim\Http\Request), Object(Slim\Http\Response))
#7 /var/www/gplus-archiver/vendor/slim/slim/Slim/App.php(406): Slim\App->callMiddlewareStack(Object(Slim\Http\Request), Object(Slim\Http\Response))
#8 /var/www/gplus-archiver/vendor/slim/slim/Slim/App.php(314): Slim\App->process(Object(Slim\Http\Request), Object(Slim\Http\Response))
#9 /var/www/gplus-archiver/public/index.php(292): Slim\App->run()
#10 {main}