WordPress allows you to install a commercial plugin from a zip file, but it won’t allow you to update the same plugin from an updated file (attempting to do so will give an error message “destination already exists” ). This is relevant to WP Academy customers attempting to update WooCommerce commercial plugins that they have downloaded from our site.
Of course you can unzip the plugin, connect your site via FTP and then over-write all the plugin files, but this is tedious. The easy way consisting of installing the plugin Update Theme and Plugins from Zip File. This will make updating a commercial plugin, as easy as installing it.