They claim its not a requirement but its shady & deceptive. I've not seen anyone get this card without already having an account.
And if you install the app and register on it, by default it'll create an account for you, I don't think there is any other way it can do.
I opened Jupiter account only thinking about possibility of getting this card (when it was not devaluated), but after opening account, my waitlist went from 9300 to 4.5 lakh lol. Their customer care claimed they'll consider the original waitlist number, but I don't think they can do it, as the queue would replace my mobile number with updated waitlist number, plus I haven't got invite till date, even though people with 80k waitlist have received invite. But yeah, now with 0.4% rewards, I'll not only not have this card but close Jupiter too, zero benefit as such, as I already have BoB Snapdeal which gives 1% with no app restrictions.