The easiest way to find something like this out is to:
(In the Arduino IDE) File > Preferences > Show verbose output during: > upload (check) > OK
Sketch > Upload Using Programmer - It's ok if the process fails. You don't need to have your programmer connected to the computer at all.
After the process finishes (or fails), examine the contents of the black console window at the bottom of the Arduino IDE window. There you will find the avrdude command generated by the Arduino IDE. You will probably need to scroll the window up to see it.
Since it sounds like you might not have the Arduino IDE installed, here's the command generated on my computer for uploading via ArduinoISP.org:
avrdude -CC:\Users\per\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino12/etc/avrdude.conf -v -patmega644p -carduinoisporg -Uflash:w:C:\Users\per\AppData\Local\Temp\arduino_build_588590/Blink.ino.hex:i
So the correct programmer ID is arduinoisporg