Adding certificate upload step

Author: SnehaGunda

articles/cosmos-db/certificate-based-authentication.md

@@ -26,7 +26,7 @@ In this step, you will register a sample web application in your Azure AD accoun
 
 1. Sign into the [Azure portal](https://portal.azure.com/).
 
-1. Open the Azure **Active Directory** pane, go to App registrations pane, and select **New registration**. 
+1. Open the Azure **Active Directory** pane, go to **App registrations** pane, and select **New registration**. 
 
    ![New application registration in Active Directory](./media/certificate-based-authentication/new-app-registration.png)
 
@@ -110,6 +110,19 @@ The above command results in the output similar to the screenshot below:
 
 1. Select **Save** after you fill out the form
 
+## Register your certificate with Azure AD
+
+You can associate the certificate-based credential with the client application in Azure AD from the Azure portal. To associate the credential, you must upload the certificate file with the following steps:
+
+In the Azure app registration for the client application:
+
+1. Sign into the [Azure portal](https://portal.azure.com/).
+
+1. Open the Azure **Active Directory** pane, go to the **App registrations** pane, and open the sample app you created in the previous step. 
+
+1. Select **Certificates & secrets** and then **Upload certificate**. Browse the certificate file you created in the previous step to upload.
+
+1. Select **Add**. After the certificate is uploaded, the thumbprint, start date, and expiration values are displayed.
 
 ## Access the keys from PowerShell