Update custom-policy-keep-me-signed-in.md

fixes https://github.com/MicrosoftDocs/azure-docs/issues/50727

Author: yoelhor

articles/active-directory-b2c/custom-policy-keep-me-signed-in.md

@@ -8,7 +8,7 @@ manager: celestedg
 ms.service: active-directory
 ms.workload: identity
 ms.topic: conceptual
-ms.date: 02/27/2020
+ms.date: 03/24/2020
 ms.author: mimart
 ms.subservice: B2C
 ---
@@ -103,7 +103,11 @@ We recommend that you set the value of SessionExpiryInSeconds to be a short peri
 </RelyingParty>
 ```
 
-4. Save your changes and then upload the file.
-5. To test the custom policy that you uploaded, in the Azure portal, go to the policy page, and then select **Run now**.
+1. Save your changes, and then upload the file.
+1. To test the custom policy you uploaded, in the Azure portal, go to the policy page, and then select **Run now**.
+1. Type your **username** and **password**, select **Keep me signed in**, and then click **sign-in**.
+1. Go back to the Azure portal. Go to the policy page, and then select **Copy** to copy the sign-in URL.
+1. In the browser address bar, remove the `&prompt=login` query string parameter, which forces the user to enter their credentials on that request.
+1. In the browser, click **Go**. Now Azure AD B2C will issue an access token without prompting you to sign-in again. 
 
 You can find the sample policy [here](https://github.com/Azure-Samples/active-directory-b2c-custom-policy-starterpack/tree/master/scenarios/keep%20me%20signed%20in).