Norton 60-day Trial Product Key

I have a newly bought HP laptop that has a 15-month subscription of Norton Antivirus. The instructions to set up the Norton Antivirus did not match with the installation options and I only have the option to set up the 60-day trial. There is no window to enter the product key.
If the 60-day trial period is over, can I just enter the product key of my 15-month subscription when the window to enter it appears or do I have to uninstall the trial version before I can continue to set up Norton Antivirus with subscription?
