diff --git a/docs/api/a-d/rewarded-video.md b/docs/api/a-d/rewarded-video.md
index ac5c2db6767af57e740441289720ef5c70e58ae1..3b86015da218ddc45407a9e8b5c582b5e84ca0f1 100644
--- a/docs/api/a-d/rewarded-video.md
+++ b/docs/api/a-d/rewarded-video.md
@@ -627,6 +627,8 @@ exports.main = async (event, context) => {
 ```js
 'use strict';
 
+const crypto = require('crypto');
+
 const db = uniCloud.database();
 
 const DEFAUTL_TIMEOUT = 30000;