I tried booting my mid 2012 mac (which is running Sierra 10.12.6) in recovery mode and opening the terminal; I would like to disable SIP. As per usual, I typed "csrutil disable", and 'command not found' was returned. I looked at klanomath's answer here (csrutil: command not found) though I didn't quite understand what he/she meant by 'booting to your main volume'. I am not sure if that is relevant here, but I am inquiring if there is any further way to disable SIP. Is high-sierra needed or helpful here?
(Also, if possible, an answer comprehensible by someone with very little background in computing or working with the terminal would be highly appreciated)
Thanks in advance.