diff --git a/lib/modules/iid/index.js b/lib/modules/iid/index.js
index 4ede6748..773fb033 100644
--- a/lib/modules/iid/index.js
+++ b/lib/modules/iid/index.js
@@ -7,8 +7,8 @@ import { getNativeModule } from '../../utils/native';
 
 import type App from '../core/app';
 
-export const MODULE_NAME = 'RNFirebaseInstanceId';
 export const NAMESPACE = 'iid';
+export const MODULE_NAME = 'RNFirebaseInstanceId';
 
 export default class InstanceId extends ModuleBase {
   constructor(app: App) {
@@ -20,20 +20,51 @@ export default class InstanceId extends ModuleBase {
     });
   }
 
-  delete(): Promise<void> {
-    return getNativeModule(this).delete();
-  }
-
+  /**
+   * Get the current Instance ID.
+   *
+   * @returns {*}
+   */
   get(): Promise<string> {
     return getNativeModule(this).get();
   }
 
-  getToken(authorizedEntity: string, scope: string): Promise<string> {
-    return getNativeModule(this).getToken(authorizedEntity, scope);
+  /**
+   * Delete the current Instance ID.
+   *
+   * @returns {*}
+   */
+  delete(): Promise<void> {
+    return getNativeModule(this).delete();
   }
 
-  deleteToken(authorizedEntity: string, scope: string): Promise<void> {
-    return getNativeModule(this).deleteToken(authorizedEntity, scope);
+  /**
+   * Get a token that authorizes an Entity to perform an action on behalf
+   * of the application identified by Instance ID.
+   *
+   * @param authorizedEntity
+   * @param scope
+   * @returns {Promise<string>}
+   */
+  getToken(authorizedEntity?: string, scope?: string): Promise<string> {
+    return getNativeModule(this).getToken(
+      authorizedEntity || this.app.options.messagingSenderId,
+      scope || '*'
+    );
+  }
+
+  /**
+   * Revokes access to a scope (action) for an entity previously authorized by getToken().
+   *
+   * @param authorizedEntity
+   * @param scope
+   * @returns {Promise<void>}
+   */
+  deleteToken(authorizedEntity?: string, scope?: string): Promise<void> {
+    return getNativeModule(this).deleteToken(
+      authorizedEntity || this.app.options.messagingSenderId,
+      scope || '*'
+    );
   }
 }