Trying to figure out how to press the pedals in Addictive Keys in FL Studio. After some searching around, I found another program that documented the ports for the various pedals:

The pedals are arranged like a piano, with the soft pedal (MIDI CC 67) on the left, the sostenuto pedal (MIDI CC 66) in the middle, and the sustain pedal (MIDI CC 64) on the right. ¹

Sending MIDI events on these ports appears to also work for Addictive Keys.

Footnotes

1. https://usermanuals.garritan.com/CFXLite/Content/keyboard_and_pedals.htm#:~:text=The%20pedals%20are%20arranged%20like%20a%20piano%2C,on%20the%20right ↩