What is the hash parameter in the VK request?

Question

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With the help of a sniffer, I found a post request that hides friends, it is not in the documentation.
This is how it looks like:

Host: vk.com
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:67.0) Gecko/20100101 Firefox/67.0
Accept: */*
Accept-Language: ru-RU,ru;q=0.8,en-US;q=0.5,en;q=0.3
Accept-Encoding: gzip, deflate, br
Referer: https://vk.com/settings?act=privacy
Content-Type: application/x-www-form-urlencoded
X-Requested-With: XMLHttpRequest
Content-Length: 59
DNT: 1
Connection: keep-alive
Cookie: remixlang=0; remixstid=1100709692_e04b26c57e5230e08e; remixflash=0.0.0; remixscreen_depth=24; remixscreen_orient=1; remixgp=93cc9f064bc7710106aa4a8ef1bc19cd; remixdt=0; tmr_detect=0%7C1562445295197; remixsid=6144f772a6cd9f5440839e6e6a2063ab6232d28f9643abdfac434e1de8f34; remixusid=Y2IzNTdlMDgzNzllZmM0Zjc0OTg5NDAy; remixseenads=0; remixrefkey=8204946586ea09651a; remixcurr_audio=173629757_456240774

Request body:

act=hide_friends&al=1&hash=72427482db36907b08&ids=404315087

I can't figure out what this hash is, it doesn't look like a token. Tried reloading the page several times but it doesn't change.
UPD: I tried to find it in the page code, but did not find it. Most likely he comes in a request