How to get a list of users who reposted a post on VK?

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How to get a list of users who reposted a post on VK?
Held a draw in the community, you need to get a list of users who reposted a post in VK and joined the community. Need a free way to solve the problem.

TargetHunter returns only users whose wall is open (does not take into account users who reposted but have closed walls). I tried vk.barkov, only 1000 users are available, the rest are available only after payment. I'm sure there are free solutions.