Changing RC port - RC_PORT_CONFIG missing

Hi, I’m trying to change the default RC port to one of the UARTs. I expected that I would need to set the RC_PORT_CONFIG parameter to TELEM 2 but the parameter is not there. Am I missing something obvious?

I’m using a Holybro Pixhawk 6c with PX4 Stable v1.14.0 and QGC v4.3.0