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:
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: