AxCrypt do indeed offer a 30-day trial and it’s activated automatically when you sign-up for an account.
There are a few ways to check if you’ve got premium. The first is to look at how many days are remaining. Because I’m not a trial user I’ve copied a picture from another website and highlighted the region you need to look at.
Another way to check if you got premium is to look at the algorithm column. If you’ve got the free version it’ll say “AES-128” and if you’ve got premium it’ll say “AES-256”.
Alternatively you can see if the progam will allow you to Secure Wipe files or use the Anonymous Rename function. If it does then you’re premium.