In which directory I should touch for rate limit on Nginx please?

Hello,
It seems there are several Wordops custom directory or configuration files of Nginx.

and it seems that we need increase rate limit setting on Nginx at https://www.nginx.com/blog/rate-limiting-nginx/

But, I can not locate or identify the Nginx configruation, anyone would like let me know which file I should touch please?

Thanks a lot