Final cut pro update without App Store?!

I need help.

I was given a Mac with Final Cut Pro already bought and loaded as a present for my graduation. Unfortunately the person who bought it for me is no longer available for me to ask him to log into his account in order for me to upgrade Final Cut Pro, and since it is not me who bought it, it does not come up under my purchases in the App Store since r was not under my account. i don't think I should have to rebuy it, since I already have it, but I recently upgraded and now Final Cut Pro won't even open. shoudknt there be somewhere other than the App Store where I can download the upgrade since I already have the program?