To remove devices from your Notification Hub via the Azure portal, you can follow these steps:
- Sign in to the Azure portal.
- Select your Notification Hub from the list of resources
- In the left-hand menu, select "Active Devices".
- Select the devices you want to remove by checking the box next to each device.
- Click the "Delete" button at the top of the page.
This will remove the selected devices from your Notification Hub.
If you do not see the "Active Devices" option in the left-hand menu, it is possible that you do not have permission to manage devices for the Notification Hub. In this case, you may need to contact your administrator to grant you the necessary permissions.
Please let us know if you have further questions or concerns on this matter. We would be happy to assist you.