update DSR doc for v4

products/digital-sales-rooms/setup-3rd-party/realtime-service-mercure.md

@@ -25,7 +25,7 @@ There are different ways to set up Mercure as listed below:
 - Access the dashboard.
 - In the **Stacks** menu item, create a new stack with the **Mercure Hub** service.
 - When creating a stack successfully, tap into the Configure button.
-- On this page, it's easy to find the [Mercure general settings](#mercure-general-settings), copy all the necessary information, and paste it into [the proper inputs of the configuration page](../configuration/plugin-config.md#realtime-service).
+- On this page, it's easy to find the [Mercure general settings](#attach-mercure-infomration-into-digital-sales-rooms), copy all the necessary information, and paste it into [the proper inputs of the configuration page](../configuration/plugin-config.md#realtime-service).
 
 ![Mercure configuration](../../../assets/products-digitalSalesRooms-mercureConfig.png)