Your website gives this process to register the key :
“DIRECTIONS
The download link for Glary Utilities Pro is provided to you above. Your registration information for Glary Utilities Pro is also given above. Download and install Glary Utilities Pro and then register it with your license key.
When registering, use the email given above; if you use any other email, it will not register properly.
You register Glary Utilities Pro by going to ACTIVATE NOW from within the main program window. At that window, click REFRESH, enter your license email and license key (given above) and hit ACTIVATE NOW. Enjoy!”
However the main program window doesn’t show any ACTIVATE NOW button, because as soon as your installer program is completed and the programe is opened for the 1st time, then it is already activated with a Pro trial licence lasting for 30 days.