Depending on where you installed Cura the default would be:
/Applications/Cura/Cura.app/Contents/MacOS/Cura
For example to get the help
/Applications/Cura/Cura.app/Contents/MacOS/Cura -h
Usage: cura.py [options] <filename>.stl
Options:
-h, --help show this help message and exit
-i PROFILEINI, --ini=PROFILEINI
Load settings from a profile ini file
-r PRINTFILE, --print=PRINTFILE
Open the printing interface, instead of the normal
cura interface.
-p PROFILE, --profile=PROFILE
Internal option, do not use!
-s, --slice Slice the given files instead of opening them in Cura
-o OUTPUT, --output=OUTPUT
path to write sliced file to
--serialCommunication=SERIALCOMMUNICATION
Start commandline serial monitor