Update enroll-renew-subscription.md

Update URL to correct url for Azure Dev Tools for teaching https://portal.azureforeducation.microsoft.com/ 
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cc: @v-shmck

Author: leestott

articles/education-hub/azure-dev-tools-teaching/enroll-renew-subscription.md

@@ -15,7 +15,7 @@ This article describes the process for enrolling in Azure Dev Tools for Teaching
 
 ## Enroll a new subscription
 
-1. Navigate to the [Azure Dev Tools for Teaching webpage](https://azure.microsoft.com/education/institutions/).
+1. Navigate to the [Azure Dev Tools for Teaching webpage](https://portal.azureforeducation.microsoft.com/).
 1. Select the **Sign up** button. 
 1. Select **Enroll or Renew** on the Azure Dev Tools for Teaching banner.
 1. Select the type of subscription you're enrolling: