Tried uploading manually via shell. Plugin could not be activated because it triggered a fatal error.
Removed *zip and nginx-folder from plugins folder, then tried installing from WordPress administration interface. Plugin could not be activated because it triggered a fatal error.
When trying to run from command line: PHP Fatal error: Call to undefined function rtCamp\WP\Nginx\plugin_dir_path() in /web/sites/[redacted]/wpcontent/plugins/nginx-helper/nginx-helper.php on line 15