If you have already subscribed to HER Premium but the features are not working please try the following:

Close the app and then restart it

Another method is the restore purchase feature that is like a reset button for premium. It won't charge you again, just sometimes needs another push to start.

You can restore your purchase by:

iOS Device:

• Go to My Profile 
• Then tap on Settings in the top, left hand corner 
• Scroll down below the list of Premium features and select "Restore Purchase"
• Then follow the steps from there

If you are using an Android device:

• Select any of the HER Premium features icons or Upgrade Access in settings
  Select Restore Subscription