Help with snapshot?

Hello, I was wondering if someone could help me out. There is an ETH contract out there that is responsible for an NFT project. That Project has a set of owners (a set of unique wallets as I understand it) I want to take a snapshot of all those wallets, that way if one wallet has 1000, they cant spread them out and add 1000 new unique wallets I mean they can, but I would have the screenshot so its docent matter... Also an added element is that the contract has multiple tokens but I am only interested in one token and I really hope that "screenshot" doesn't mean I have to go on etherscen and acutely take snapshot of every page/ wallet Fingers crossed. Also, I know it is possible because a few websites like opensea can isolate the holders of just that token. if anyone has any tips or can point me in the right direction, I would greatly appreciate it.