HLTV is not a plugin. It is a standalone process that connects to the server (like any other player) and allows people to join it and see what is going on in the server. It comes with every installation of a standalone HLDS (free with hldsupdatetool).
https://support.steampowered.com/kb_...6758-TCMF-2234
https://support.steampowered.com/kb_...1990-UAVN-3335
There is one plugin that you can use to make the HLTV connect and disconnect on command and it's called "HLTV Report" in the Approved Plugins section. But, if you just want it for checking for hackers then you can simply have it connect (and record if you want) to the server and then you can connect to the HLTV and see what it sees.
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