Before you launch the installer, please select / highlight your keycode and hit CTRL+C on your keyboard. It will then automatically fill out the box with the copied keycode once you launch the installer.
If this workaround doesn't solve the issue, please submit a support ticket on this page (top right corner). You can also reach out to us on our Discord channel and submit a support ticket there, or in case you want to join an amazing community full of fans and gamers.