How to block bad bot in nginx?

I have tried using a code from a guy in github but it didn't work for me
## Add here all user agents that are to be blocked.
map $http_user_agent $bad_bot {
default 0;
~*^Lynx 0; # Let Lynx go through
libwww-perl 1;
~*(?i)(httrack|htmlparser|libwww|JikeSpider|proximic|Sosospider|Baiduspider|msnbot|BBBike|WWWOFFLE|Widow|SuperHTTP|BlackWidow|HTTrack|Java|Pixray|CPython|Spinn3r|Abonti|MSIECrawler|Baiduspider|Yandex|Siteimprove|Aboundex|80legs|360Spider|^Java|Cogentbot|^Alexibot|^asterias|^attach|^BackDoorBot|^BackWeb|Bandit|^BatchFTP|^Bigfoot|^Black.Hole|^BlackWidow|^BlowFish|^BotALot|Buddy|^BuiltBotTough|^Bullseye|^BunnySlippers|^Cegbfeieh|^CheeseBot|^CherryPicker|^ChinaClaw|Collector|Copier|^CopyRightCheck|^cosmos|^Crescent|^Custo|^AIBOT) 1;
}


## Add here all referrers that are to blocked.
map $http_referer $bad_referer {
default 0;
~(?i)(adult|babes|click|diamond|forsale|girl|jewelry|love|nudit|organic|poker|porn|poweroversoftware|sex|teen|webcam|zippo|casino|replica) 1;
}


## Add here all hosts that should be spared any referrer checking.
geo $bad_referer {
127.0.0.1 0;
192.168.1.0/24 0;
}

Do I have to install any addon ?
Anyone have any script to block bad bot ?