Betterment I just saw that it is a numeque code 😆.
I can activate it whenever I want, I suppose at the end of my current subscription and even six months later I suppose? If I activate it after the end of my current subscription, I will not be able to access my current library during this time. I'm asking because I don't have much time to play and I'd like to use the code in about 6 months.

Yes, that is independent of the Playstation.