To insert a licence key, press 'Cancel', and choose 'Help' from the main menu.
Choose 'Enter Licence Key...'
You have several options to insert a key. You may either browse for the file, or more conveniently, you may choose to drag and drop the key onto the large white area. Key files are normally delivered in ZIP files - you do not need to extract the key (the program will do this automatically for you).
When key insertion key is successful, you'll receive the following message: