Use php libarary in wordpress plugins

I need to work with excel files in my wordpress plugin and I should use the PhpSpreadsheet library. The problem is I don’t know how to import this library in my plugin? Should I use autoload or composer? Since this plugin is for a customer, it’s better to be a way the requires least modification to the site itself.

You can always use the Composer when making a plugin and require all its dependencies. But as MikenGarrett said, finally you have to bundle all the required vendors into the plugin as a whole package.

There are WordPress repository, containing /vendor/ directory¹ and their development environment containing composer.json file declaring production-dependencies ('require')².

But using Composer you will get a /vendor/ directory and vendor directory is excluded while scraping strings for translation in WordPress plugin repository. Some people suggest changing the name of the /vendor/ directory into something else like /packages/ to scrape their strings too.

Thanks to Pascal Birchler, Tor-Björn Fjellner, Aristeides Stathopoulos for assisting in this matter.