diff --git a/README.md b/README.md
index 2bdbd28..b814c87 100644
--- a/README.md
+++ b/README.md
@@ -38,6 +38,8 @@ export GOOGLE_ADS_REFRESH_TOKEN=xxxx
 export GOOGLE_ADS_LOGIN_CUSTOMER_ID=1234567890  # sin guiones
 
 export ANTHROPIC_API_KEY=sk-ant-xxxx
+
+export SLACK_WEBHOOK_URL=xxx
 ```
 
 ---