Hi there,
A couple of quick questions. First is your subscription active? If not what is the latest version you’re subscribed up to?
The reason you’re seeing ‘Subscribe’ is likely because your subscription is not currently active. If you feel this is in error and you are currently subscribed to UE4, shoot an email to accounts@unrealengine.com so they can look into the issue further. If you’ve subscribed in the past, try an older version of the engine to see which ones were available during your active subscription.
Hope that helps! 