How to block ipv6 range in nginx?

Question

Nginx

Faced with the fact that there was a sharp surge of direct visits to the site that do nothing. I am very much concerned about the negative markup of the PF.
I figured out the scheme of bots, but I can’t figure out exactly how to block them. They come from ipv6 addresses, for example:
2a05:fb42:17f:*:*:*:*
With ipv4 it is clear how to block one address.
I tried to set such masks: deny 2a05:fb42:0000:0000:0000:0000:0000:0000/32;, but I don't understand how it works.
How can this problem be solved?