Fatal error: Uncaught Error: Interface "Composer\Plugin\PluginInterface" not found in /var/www/html1/wp-content/plugins/zettle-pos-integration/vendor/php-http/discovery/src/Composer/Plugin.php:39 Stack trace: #0 {main} thrown in /var/www/html1/wp-content/plugins/zettle-pos-integration/vendor/php-http/discovery/src/Composer/Plugin.php on line 39