Up until now your PRO license would expire without warning, meaning you could be left without access to PRO.
We fixed that.
As of Version 18.104.22.168 the PRO license will be a recurring Subscription that you can manage in your Microsoft account page! You can also get there via the Drawboard PDF settings menu, where it says Drawboard PDF PRO. You will find a link to manage your subscriptions.
If you have any further support questions, please write to us at firstname.lastname@example.org