the link below did not work for me, though logged into my account:
Click the highlighted text to be redirected to the page here at WPMU DEV where you can enable your site for all the goodies: Update Notifications Sites.
There’s also a link to that page in your account menu here at WPMU DEV. Click your avatar in the header, then click the “Update Notifications” link.
For reference, here’s the direct URL: https://premium.wpmudev.org/wp-admin/users.php?page=wdpun
Once on the Update Notifications page, click the “Enable” button at the far right of the row corresponding to the site you want to enable.