Elevon Control in ArduPlane 3.4

Hello, I am trying to set up my old APM 2.6 to use it for a small scratch build flying wing. I am looking at the docs here and it says only that the parameter to set would be ‘SERVO1_FUNCTION’, however, I go to my full parameter list and look and I do not have that param… I did a search even and there is nothing under that name. Can anyone help me to set up elevon on APM2.6? I am basically just trying to use it for stabilization and auto-leveling features. No GPS. My firmware version is 3.4.0… thank you.

The documentation reflects the latest firmware, version 3.8.

You can find some information here about how Elevons used to be configured: http://ardupilot.org/plane/docs/plane-3-7-to-3-8-migration.html#change-to-elevon-vtail-and-flaperon-configuration