GDPR Implementation requirements are fulfilled.

asystgrade/classes/privacy/provider.php

+<?php
+namespace local_asystgrade\privacy;
+
+/**
+ * https://moodledev.io/docs/4.5/apis/subsystems/privacy#implementation-requirements
+ * GDPR Implementation requirements
+ * In order to let Moodle know that you have audited your plugin, and that you do not store
+ * any personal user data, you must implement the \core_privacy\local\metadata\null_provider
+ * interface in your plugin's provider.
+ */
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Privacy Subsystem implementation for local_asystgrade.
+ *
+ * @package    local_asystgrade
+ */
+class provider implements \core_privacy\local\metadata\null_provider {
+
+    /**
+     * Get the reason why this plugin stores no data.
+     *
+     * @return  string
+     */
+    public static function get_reason() : string {
+        return get_string('privacy:metadata', 'local_asystgrade');
+    }
+}

asystgrade/lang/en/local_asystgrade.php

@@ -10,3 +10,4 @@
 $string['pluginname']       = 'ASYST API Moodle integration plugin';
 $string['apiendpoint']      = 'API Endpoint';
 $string['apiendpoint_desc'] = 'The endpoint of the AsystGrade API.';
+$string['privacy:metadata'] = 'The AsystGrade plugin does not store any personal data.';